umu.sePublications
Change search
Refine search result
1 - 29 of 29
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1.
    Bengtsson, Sara
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Maja
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Nitsch, Roger
    University of Zürich, Division of Psychiatry Research and Psychogeriatric Medicine,.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Brief but Chronic Increase in Allopregnanolone Cause Accelerated ADPathology Differently in Two Mouse Models2013In: Current Alzheimer Research, ISSN 1567-2050, Vol. 10, no 1, 38-47 p.Article in journal (Refereed)
    Abstract [en]

    Abstract: Previously, we have shown that chronic treatment with allopregnanolone (ALLO) for three months impaired learning function in the Swe/PS1 mouse model. ALLO is a neurosteroid, produced in the CNS and a GABAA receptor agonist. ALLO modulates the general inhibitory system in the CNS by enhancing the effect of GABA. Chronic treatment with other GABAA receptor active compounds, such as benzodiazepines, ethanol and medroxy-progesterone acetate has been associated to cognitive decline and/or increased risk for dementia. In this study, we sufficed with a treatment period of one month for the Swe/PS1 mouse, and included another Alzheimer’s disease mouse model; the Swe/Arc model. We found that one month of chronic treatment with elevated ALLO levels within physiological range impaired learning and memory function in the Swe/Arc female and male mice. Male Swe/PS1 mice also showed marginally impaired function, while the female mice did not. Furthermore, the chronic ALLO treatment caused increased levels of soluble Aβ in the Swe/PS1 mouse model while the levels were unchanged in the Swe/Arc model. Therefore, both Swe/Arc and Swe/PS1 mice showed signs of accelerated disease progression. Still, further studies are required to determine the mechanisms behind the cognitive impairment and the increased Aβ-levels caused by mildly elevated ALLO-levels. learning function in the Swe/PS1 mouse model. ALLO is a neurosteroid, produced in the CNS and a GABAA receptor agonist. ALLO modulates the general inhibitory system in the CNS by enhancing the effect of GABA. Chronic treatment with other GABAA receptor active compounds, such as benzodiazepines, ethanol and medroxy-progesterone acetate has been associated to cognitive decline and/or increased risk for dementia. In this study, we sufficed with a treatment period of one month for the Swe/PS1 mouse, and included another Alzheimer’s disease mouse model; the Swe/Arc model. We found that one month of chronic treatment with elevated ALLO levels within physiological range impaired learning and memory function in the Swe/Arc female and male mice. Male Swe/PS1 mice also showed marginally impaired function, while the female mice did not. Furthermore, the chronic ALLO treatment caused increased levels of soluble Ab in the Swe/PS1 mouse model while the levels were unchanged in the Swe/Arc model. Therefore, both Swe/Arc and Swe/PS1 mice showed signs of accelerated disease progression. Still, further studies are required to determine the mechanisms behind the cognitive impairment and the increased Aβ-levels caused by mildly elevated ALLO-levels.

  • 2.
    Bengtsson, Sara K.
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Maja
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Nitsch, Roger M.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Brief but Chronic Increase in Allopregnanolone Cause Accelerated AD Pathology Differently in Two Mouse Models2013In: Current Alzheimer Research, ISSN 1567-2050, Vol. 10, no 1, 38-47 p.Article in journal (Refereed)
    Abstract [en]

    Previously, we have shown that chronic treatment with allopregnanolone (ALLO) for three months impaired learning function in the Swe/PS1 mouse model. ALLO is a neurosteroid, produced in the CNS and a GABA(A) receptor agonist. ALLO modulates the general inhibitory system in the CNS by enhancing the effect of GABA. Chronic treatment with other GABA(A) receptor active compounds, such as benzodiazepines, ethanol and medroxy-progesterone acetate has been associated to cognitive decline and/or increased risk for dementia. In this study, we sufficed with a treatment period of one month for the Swe/PS1 mouse, and included another Alzheimer's disease mouse model; the Swe/Arc model. We found that one month of chronic treatment with elevated ALLO levels within physiological range impaired learning and memory function in the Swe/Arc female and male mice. Male Swe/PS1 mice also showed marginally impaired function, while the female mice did not. Furthermore, the chronic ALLO treatment caused increased levels of soluble A beta in the Swe/PS1 mouse model while the levels were unchanged in the Swe/Arc model. Therefore, both Swe/Arc and Swe/PS1 mice showed signs of accelerated disease progression. Still, further studies are required to determine the mechanisms behind the cognitive impairment and the increased A beta-levels caused by mildly elevated ALLO-levels.

  • 3.
    Bengtsson, Sara K.
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Maja
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Chronic Allopregnanolone Treatment Accelerates Alzheimer's Disease Development in A beta PP(Swe)PSEN1(Delta E9) Mice2012In: Journal of Alzheimer's Disease, ISSN 1387-2877, E-ISSN 1875-8908, Vol. 31, no 1, 71-84 p.Article in journal (Refereed)
    Abstract [en]

    The endogenous neurosteroid allopregnanolone alters neuronal excitability via modulation of the GABA(A) receptor and causes decreased neurotransmission. In Alzheimer's disease (AD), neurotransmission seems to alter the levels of toxic intracellular amyloid-beta (A beta) oligomers, which are implicated in AD pathogenesis and cause cognitive decline. Inhibition of synaptic activity has been shown to increase levels of intracellular A beta. Allopregnanolone at endogenous stress levels inhibits synaptic activity and could have similar effects. By using a transgenic A beta PP(Swe)PSEN1(Delta E9) mouse model for AD, we observed that chronic allopregnanolone treatment for three months with stress levels of allopregnanolone impaired learning in the Morris water maze. The learning impairment was seen one month after the end of treatment. Chronic allopregnanolone treatment also led to increased levels of soluble A beta in the brain, which could be a sign of advanced pathogenesis. Since the learning and memory of wild-type mice was not affected by the treatment, we propose that chronic allopregnanolone treatment accelerates the pathogenesis of AD. However, further studies are required in order to determine the underlying mechanism.

  • 4.
    Bengtsson, Sara
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Lundgren, Per
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Gouissem, Samira
    Umecrine AB.
    Johansson, Maja
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Chronic allopregnanolone elevation cause altered plaque production in Swe/PS1 miceManuscript (preprint) (Other academic)
    Abstract [en]

    Abstract. We have previously shown that chronic elevation of the neurosteroid allopregnanolone caused learning dysfunction and increased levels of soluble Aβ in the Swe/PS1 mouse model. The mechanism behind these findings is however unknown. We further investigated the brain tissue of these mice to identify any effects on congophilic plaque burden, Aβ42-specific plaque burden and synaptic function. We found a significant reduction in the average size of the congophilic core of neuritic plaques after chronic allopregnanolone treatment compared to vehicle. This seems to be caused by an altered plaque production, leading to more abundant, but smaller neuritic plaques. We may also have detected a decrease in the amount of synaptophysin, and thus synaptic function among the same mice. However, the long interval between the end of treatment and tissue collection possibly allowed time for recovery and only minor differences were noted. We found that the natural relationship between levels of insoluble Aβ, congophilic and Aβ42-specific plaque load was disrupted after chronically elevated allopregnanolone levels. Furthermore, the levels of syn-aptophysin and insoluble Aβ became more important in the relationship to learning and memory. The causality of these factors is still unknown and further studies are required to fully understand the effect of neurosteroids on AD development.

  • 5.
    Birzniece, Vita
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Inga-Maj
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Lindblad, Charlotte
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Lundgren, Per
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Löfgren, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Olsson, Tommy
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Ragagnin, Gianna
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Taube, Magdalena
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Turkmen, Sahruh
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wahlström, Göran
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Pharmacology.
    Wang, Ming-De
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wihlbäck, Anna-Carin
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Zhu, Di
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Neuroactive steroid effects on cognitive functions with a focus on the serotonin and GABA systems.2006In: Brain Research Reviews, ISSN 0165-0173, E-ISSN 1872-6321, Vol. 51, no 2, 212-239 p.Article in journal (Refereed)
  • 6.
    Birzniece, Vita
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, I-M
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, MD
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, T
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Olsson, T
    Ovarian hormone effects on 5-hydroxytryptamine (2A) and 5-hydroxytryptamine (2C) receptor mRNA expression in the ventral hippocampus and frontal cortex of female rats.2002In: Neuroscience Letters, ISSN 0304-3940, E-ISSN 1872-7972, Vol. 319, no 3, 157-161 p.Article in journal (Refereed)
    Abstract [en]

    Alterations in female gonadal hormones are associated with anxiety and mood changes. The aim of the present study was to determine influences of chronic gonadal hormone supplementation on 5-HT(2A) and 5-HT(2C) receptor mRNA levels in the ventral hippocampus and the frontal cerebral cortex. Ovariectomized adult female Sprague-Dawley rats (n=37) received implantation of subcutaneous pellets containing different dosages of 17beta-estradiol alone or in combination with progesterone, or placebo pellets, for 2 weeks. Serotonin receptor mRNA levels were analyzed by in situ hybridization in the ventral hippocampus and 5-HT(2A) receptor mRNA also in the frontal cortex. Estradiol treatment in combination with low-dose progesterone increased 5-HT(2A) receptor mRNA by 43% in the CA2 region of the ventral hippocampus, while estradiol combined with high-dose progesterone increased the expression of this gene by 84% in ventral CA1. 5-HT(2A) mRNA expression in the frontal cortex was not influenced by hormone manipulation. 5-HT(2C) receptor gene expression was in the ventral hippocampus decreased in the CA2, ventral CA1 and the subiculum subregions by high-dose estradiol treatment (8-20% decreases). Effects on mood by gonadal hormones can be mediated, at least partly, through influences on 5-HT(2A) and 5-HT(2C) receptor expression.

  • 7.
    Birzniece, Vita
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, I-M
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, MD
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Seckl, JR
    Bäckström, T
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Olsson, T
    Serotonin 5-HT(1A) receptor mRNA expression in dorsal hippocampus and raphe nuclei after gonadal hormone manipulation in female rats.2001In: Neuroendocrinology, ISSN 0028-3835, E-ISSN 1423-0194, Vol. 74, no 2, 135-142 p.Article in journal (Refereed)
    Abstract [en]

    Female ovarian steroids influence mood and cognition, an effect presumably mediated by the serotonergic system. A key receptor in this interplay may be the 5-HT(1A) receptor subtype. We gave adult ovariectomized female rats subcutaneous pellets containing different dosages of 17 beta-estradiol alone or in combination with progesterone, or placebo pellets, for 2 weeks. 5-HT(1A) receptor mRNA levels were analyzed by in situ hybridization in the dorsal hippocampus, dorsal and median raphe nuclei, and entorhinal cortex. Estradiol treatment alone reduced 5-HT(1A) gene expression in the dentate gyrus and the CA2 region (17 and 19% decrease, respectively). Estradiol combined with progesterone supplementation increased 5-HT(1A) gene expression versus placebo in the CA1 and CA2 subregions of the dorsal hippocampus (16 and 30% increase, respectively). Concomitantly, 5-HT(1A) mRNA expression was decreased by 13% in the ventrolateral part of the dorsal raphe nuclei, while no changes were found in the median raphe nucleus and entorhinal cortex. Chronic effects of ovarian hormones on 5-HT(1A) receptor mRNA expression appear tissue-specific and involve hippocampal subregions and the raphe nuclei. Modulation of 5-HT(1A) receptor gene expression may be of importance for gonadal steroid effects on mood and cognition. Copyright 2001 S. Karger AG, Basel

  • 8.
    Bäckström, Torbjörn
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Andersson, Agneta
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Andreén, Lotta
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Birzniece, Vita
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bixo, Marie
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Björn, Inger
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Haage, David
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Isaksson, Monica
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Inga-Maj
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Lindblad, Charlott
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Lundgren, Per
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Nyberg, Sigrid
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Ödmark, Inga-Stina
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Strömberg, Jessica
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Sundström-Poromaa, Inger
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Turkmen, Sahruh
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wahlström, Göran
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wihlbäck, Anna-Carin
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Zhu, Di
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Zingmark, Elisabeth
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Pathogenesis in menstrual cycle-linked CNS disorders.2003In: Annals of the New York Academy of Sciences, ISSN 0077-8923, E-ISSN 1749-6632, Vol. 1007, 42-53 p.Article, review/survey (Other academic)
  • 9.
    Bäckström, Torbjörn
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Andreen, Lotta
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Birzniece, Vita
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Björn, Inger
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Inga-Maj
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Nordenstam-Haghjo, Maud
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Nyberg, Sigrid
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Sundström-Poromaa, Inger
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wahlström, Göran
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Zhu, Di
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    The role of hormones and hormonal treatments in premenstrual syndrome2003In: CNS Drugs, ISSN 1172-7047, E-ISSN 1179-1934, Vol. 17, no 5, 325-342 p.Article in journal (Refereed)
    Abstract [en]

    Premenstrual syndrome (PMS) is a menstrual cycle-linked condition with both mental and physical symptoms. Most women of fertile age experience cyclical changes but consider them normal and not requiring treatment. Up to 30% of women feel a need for treatment. The aetiology is still unclear, but sex steroids produced by the corpus luteum of the ovary are thought to be symptom provoking, as the cyclicity disappears in anovulatory cycles when a corpus luteum is not formed. Progestogens and progesterone together with estrogen are able to induce similar symptoms as seen in PMS. Symptom severity is sensitive to the dosage of estrogen. The response systems within the brain known to be involved in PMS symptoms are the serotonin and GABA systems. Progesterone metabolites, especially allopregnanolone, are neuroactive, acting via the GABA system in the brain. Allopregnanolone has similar effects as benzodiazepines, barbiturates and alcohol; all these substances are known to induce adverse mood effects at low dosages in humans and animals. SSRIs and substances inhibiting ovulation, such as gonadotrophin-releasing hormone (GnRH) agonists, have proven to be effective treatments. To avoid adverse effects when high dosages of GnRH agonists are used, add-back hormone replacement therapy is recommended. Spironolactone also has a beneficial effect, although not as much as SSRIs and GnRH agonists.

  • 10.
    Bäckström, Torbjörn
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wahlström, Göran
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology. Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Wahlström, Kerstin
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology. Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Zhu, Di
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology. Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Wang, Ming-De
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology. Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Isoallopregnanolone; an antagonist to the anaesthetic effect of allopregnanolone in male rats2005In: European Journal of Pharmacology, ISSN 0014-2999, E-ISSN 1879-0712, Vol. 512, no 1, 15-21 p.Article in journal (Refereed)
    Abstract [en]

    The interaction of isoallopregnanolone (3β-OH-5α-pregnan-20-one) on allopregnanolone (3α-OH-5α-pregnan-20-one) induced anaesthesia was studied in male rats using burst suppression of 1 s (“silent second”) with an electroencephalographic-threshold method. The i.v. administration of isoallopregnanolone was varied in relation to induction of “silent second”. Pre-treatment with isoallopregnanolone (12.5–50 mg/kg iv) 2 min prior to the threshold test gave an increase in the threshold dose of allopregnanolone(ANOVA df(3;36), F=13.61, P<0.001), which was dose dependent (r=0.73, b [slope]=0.08, df=38, P<0.001). After isoallopregnanolone pre-treatment, but not in the controls, anaesthesia time was positively related to the dose of allopregnanolone (r=0.52, b=1.72, df=28,P<0.01). Anaesthesia times were not influenced by a corresponding administration of isoallopregnanolone immediately after induction of “silent second”. When allopregnanolone and isoallopregnanolone were infused together at molar ratios of 1:1, 1:1.23, 1:1.43, a linear increase of the threshold doses of allopregnanolone was seen in relation to the dose of isoallopregnanolone (r=0.86, b=0.40, df=8,P<0.01). Thus isoallopregnanolone can antagonise the anaesthetic action of allopregnanolone.

     

  • 11.
    Hedström, Helena
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bixo, Marie
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Nyberg, Sigrid
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Turkmen, Sahruh
    Sundsvalls sjukhus, Obstetrik och gynekologi.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Does chronic endogenous exposure to neuroactive steroids change receptor sensitivity to allopregnanolone in humans?Manuscript (preprint) (Other academic)
  • 12.
    Hedström, Helena
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bixo, Marie
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Nyberg, Sigrid
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Gideonsson, Ida
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Turkmen, Sahruh
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Women with polycystic ovary syndrome have elevated serum concentrations of and altered GABA A receptor sensitivity to allopregnanolone2015In: Clinical Endocrinology, ISSN 0300-0664, E-ISSN 1365-2265, Vol. 83, no 5, 643-650 p.Article in journal (Refereed)
    Abstract [en]

    ObjectiveSeveral studies have reported that -aminobutyric acid (GABA) ergic circuits are involved in the pathophysiology of polycystic ovary syndrome (PCOS). The progesterone metabolite allopregnanolone is a potent GABA(A)-receptor-modulating steroid, and patients may have increased concentrations of allopregnanolone or altered GABA(A) receptor sensitivity. We investigated both of these possibilities in this study. PatientsWe enrolled 9 women with PCOS and 24 age-matched eumenorrhoeic controls, who were divided into two groups by body mass index (BMI) (16 normal weight and 8 overweight). MeasurementsWe investigated the effects of allopregnanolone injection on GABA(A) receptor sensitivity in both groups of women. All women received a single intravenous dose of allopregnanolone (0050mg/kg). GABA(A) receptor sensitivity was assessed with the saccadic eye velocity (SEV) over 30 degrees (SEV30 degrees), the SEV30 degrees/allopregnanolone concentration ([Allo]) ratio, and sedation, which were measured together with serum allopregnanolone at intervals for 180min after injection. The controls were tested in the follicular phase of the menstrual cycle. ResultsBaseline allopregnanolone concentrations were higher in the PCOS women than in the normal-weight (P=0034) and overweight controls (P=0004). The allopregnanolone concentrations after injection were higher in the PCOS women (P=0006) and overweight controls (P=0037) than in the normal-weight controls. All groups showed a decline in the SEV30 degrees/[Allo] ratio after injection. Allopregnanolone had a smaller effect on the SEV30 degrees/[Allo] ratio in the overweight women (PCOS, P=0032; controls, P=0007) than in the normal-weight controls. The sedation score after allopregnanolone injection was lower in the PCOS patients than in the controls, but was not different between the two control groups. ConclusionsPCOS women had elevated baseline allopregnanolone concentrations compared with follicular-phase controls. All overweight women (PCOS and controls) were less sensitive to allopregnanolone than normal-weight controls.

  • 13.
    Hedström, Helena
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Nyberg, Sigrid
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bixo, Marie
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Allopregnanolone, a GABA-A receptor agonist, decreases gonadotropin levels in healthy fertile women but not in women with polycystic ovary syndromeManuscript (preprint) (Other academic)
  • 14.
    Lundgren, Per
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Strömberg, Jessica
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Allopregnanolone-stimulated GABA-mediated chloride ion flux is inhibited by 3beta-hydroxy-5alpha-pregnane-20-one (isoallopregnanolone)2003In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 982, no 1, 45-53 p.Article in journal (Refereed)
  • 15.
    Mennerick, Steven
    et al.
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    He, Yejun
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    Jiang, Xin
    Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, Missouri .
    Manion, Brad D
    Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri .
    Wang, Mingde
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    Shute, Amanda
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    Benz, Ann
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    Evers, Alex S
    Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, Missouri.
    Covey, Douglas F
    Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, Missouri.
    Zorumski, Charles F
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    Selective antagonism of 5alpha-reduced neurosteroid effects at GABA(A) receptors2004In: Molecular Pharmacology, ISSN 0026-895X, E-ISSN 1521-0111, Vol. 65, no 5, 1191-1197 p.Article in journal (Refereed)
    Abstract [en]

    Although neurosteroids have rapid effects on GABA(A) receptors, study of steroid actions at GABA receptors has been hampered by a lack of pharmacological antagonists. In this study, we report the synthesis and characterization of a steroid analog, (3alpha,5alpha)-17-phenylandrost-16-en-3-ol (17PA), that selectively antagonized neurosteroid potentiation of GABA responses. We examined 17PA using the alpha1beta2gamma2 subunit combination expressed in Xenopus laevis oocytes. 17PA had little or no effect on baseline GABA responses but antagonized both the response augmentation and the direct gating of GABA receptors by 5alpha-reduced potentiating steroids. The effect was selective for 5alpha-reduced potentiating steroids; 5beta-reduced potentiators were only weakly affected. Likewise, 17PA did not affect barbiturate and benzodiazepine potentiation. 17PA acted primarily by shifting the concentration response for steroid potentiation to the right, suggesting the possibility of a competitive component to the antagonism. 17PA also antagonized 5alpha-reduced steroid potentiation and gating in hippocampal neurons and inhibited anesthetic actions in X. laevis tadpoles. Analogous to benzodiazepine site antagonists, the development of neurosteroid antagonists may help clarify the role of GABA-potentiating neurosteroids in health and disease.

  • 16.
    Mozibur, Rahman
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Zhu, Di
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Lindblad, Charlotte
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Inga-Maj
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Holmberg, Elinor
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Isaksson, Monica
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Ming-De
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    GABA-site antagonism and pentobarbital actions do not depend on the α-subunit type in the recombinant rat GABA-A receptor2006In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 187, no 4, 479-488 p.Article in journal (Refereed)
  • 17.
    Rahman, Mozibur
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Borra, Vijaya B
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Isaksson, Monica
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Inga-Maj
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Ragagnin, Gianna
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Ming-De
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    A comparison of the pharmacological properties of recombinant human and rat α1β2γ2L GABAA receptors in Xenopus oocytes2008In: Clinical and experimental pharmacology & physiology, ISSN 0305-1870, E-ISSN 1440-1681, Vol. 35, no 9, 1002-1011 p.Article in journal (Refereed)
    Abstract [en]

    In the present study, we compared the pharmacology, particularly neurosteroid modulation of the GABA(A) receptor, between human and rat alpha(1)beta(2)gamma(2)(L) GABA(A) receptors and between human receptors containing the long (L) and short (S) forms of the gamma(2)-subunit. We observed that maximum responses to GABA were significantly higher with the human alpha(1)beta(2)gamma(2)(L) receptor compared with the rat receptor. In terms of neurosteroid modulation, increases in the EC(15) response to GABA induced by 3alpha-OH-5beta-pregnan-20-one (3alpha5betaP), 5alpha-androstane-3alpha,17beta-diol (3alpha5alphaADL) and 5alpha-pregnane-3alpha,20beta-diol (3alpha5alpha-diol) were significantly greater for the rat compared with the human receptor. Responses to 30 micromol/L GABA were inhibited by 3beta-OH-5alpha-pregnan-20-one (UC1010) and 5beta-pregnan-3beta,20(R)-diol (UC1020) to a greater degree for human and rat receptors, respectively. Responses to GABA + 3alpha5alphaTHDOC were inhibited by 5alpha-pregnan-3beta,20(S)-diol (UC1019) and pregnenolone sulphate to a greater degree for human and rat receptors, respectively. The GABA dose-response curves for human alpha(1)beta(2)gamma(2)(S) and alpha(1)beta(2)gamma(2)(L) receptors were identical. However, the maximum GABA-evoked current, the direct gating effect of pentobarbital and the allosteric potentiation of the GABA EC(15) response by 3alpha5alphaTHDOC and 3alpha5betaP were significantly higher with alpha(1)beta(2)gamma(2)(S) than alpha(1)beta(2)gamma(2)(L) receptors. Inhibition of the response to 30 micromol/L GABA by UC1010 and UC1020 was greater for a(1)beta(2)gamma(2)(L) and alpha(1)beta(2)gamma(2)(S) receptors, respectively. Inhibition of responses to 3alpha5alphaTHDOC + GABA by UC1019 and UC1010 was significantly higher for alpha(1)beta(2)gamma(2)(L) receptors. In conclusion, the site of activation by GABA and neurosteroid modulation differ between human and rat alpha(1)beta(2)gamma(2)(L) receptors, as well as between human receptors containing the L and S splice variants of the gamma(2)-subunit.

  • 18.
    Rahman, Mozibur
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Isaksson, Monica
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Inga-Maj
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Ragagnin, Gianna
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    backström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Ming-De
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Functional difference between recombinant human and rat α1β2γ2L GABAA receptorsManuscript (Other academic)
  • 19.
    Rahman, Mozibur
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Lindblad, Charlotte
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Inga-Maj
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Ming-De
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Neurosteroid modulation of recombinant rat alpha5beta2gamma2L and alpha1beta2gamma2L GABA(A) receptors in Xenopus oocyte.2006In: Eur J Pharmacol, ISSN 0014-2999, Vol. 547, no 1-3, 37-44 p.Article in journal (Refereed)
  • 20.
    Strömberg, Jessica
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Lundgren, Per
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Taube, Magdalena
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Haage, David
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    The effect of the neuroactive steroid 5β-pregnane-3β, 20(R)-diol on the time course of GABA evoked currents is different to that of pregnenolone sulphate2009In: European Journal of Pharmacology, ISSN 0014-2999, E-ISSN 1879-0712, Vol. 605, no 1-3, 78-86 p.Article in journal (Refereed)
    Abstract [en]

    The endogenous progesterone metabolite allopregnanolone has a number of properties including anesthetic, sedative, antiepileptic, anxiolytic, impaired memory function and negative mood symptoms. Allopregnanolone is a potent positive GABA(A) receptor function modulators. In contrast, 3beta-hydroxy-steroids (3beta-steroids) usually modulate the GABA(A) receptor negatively. They have attracted some interest for their possible use as therapeutic agents that could counteract the negative symptoms induced by allopregnanolone. Two hypotheses for the action of 3beta-steroids have been proposed: 1) 3beta-steroids act in a similar way to pregnenolone sulphate, which non-competitively reduces GABA(A) receptor activity. 2) 3beta-steroids specifically antagonize the effect of allopregnanolone. We have therefore tried to clarify this issue by comparing the effect of pregnenolone sulphate and 5beta-pregnane-3beta, 20(R)-diol on the GABA-evoked currents by the patch clamp technique on neurons from the medial preoptic nucleus. Both pregnenolone sulphate and 5beta-pregnane-3beta, 20(R)-diol increase the desensitization rate of the current response evoked by a 2 s GABA application. However, their effects on other parameters of the GABA evoked currents differed in degree and sometimes even in direction. The actions of pregnenolone sulphate and 5beta-pregnane-3beta, 20(R)-diol were not altered in the presence of allopregnanolone, which indicates that they do not directly interact with allopregnanolone. In addition, when 5beta-pregnane-3beta, 20(R)-diol was tested on spontaneous inhibitory postsynaptic currents (sIPSCs), it dramatically reduced the allopregnanolone-induced prolongation of the decay time constant but it had no effect on the decay under control conditions. In conclusion, the effect of 5beta-pregnane-3beta, 20(R)-diol on GABA-evoked currents is different to that of pregnenolone sulphate in medial preoptic nucleus neurons.

  • 21.
    Strömberg, Jessica
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Lundgren, Per
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Taube, Magdalena
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Haage, David
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    The neuroactive steroid 5beta-pregnane-3beta, 20(R)-diol alters the kinetic properties of the GABA-A receptor differently from pregnenolone-sulfateManuscript (Other academic)
  • 22.
    Turkmen, Sahruh
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bixo, Marie
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Hedström, Helena
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Gideonsson, Ida
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Nyberg, Sigrid
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    The author's reply: Blood allopregnanolone levels in women with polycystic ovary syndrome2016In: Clinical Endocrinology, ISSN 0300-0664, E-ISSN 1365-2265, Vol. 85, no 1, 152-154 p.Article in journal (Refereed)
  • 23.
    Wang, Mingde
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Neurosteroids and GABA-A receptor function2011In: Frontiers in Neuroendocrine science, Vol. 2, no 44, 1-23 p.Article in journal (Refereed)
    Abstract [en]

    Neurosteroids represent a class of endogenous steroids that are synthesized in the brain, the adrenals, and the gonads and have potent and selective effects on the GABAA-receptor. 3α-hydroxy A-ring reduced metabolites of progesterone, deoxycorticosterone, and testosterone are positive modulators of GABAA-receptor in a non-genomic manner. Allopregnanolone (3α-OH-5α-pregnan-20-one), 5α-androstane-3α, 17α-diol (Adiol), and 3α5α-tetrahydrodeoxycorticosterone (3α5α-THDOC) enhance the GABA-mediated Cl- currents acting on a site (or sites) distinct from the GABA, benzodiazepine, barbiturate, and picrotoxin binding sites. 3α5α-P and 3α5α-THDOC potentiate synaptic GABAA-receptor function and activate δ-subunit containing extrasynaptic receptors that mediate tonic currents. On the contrary, 3β-OH pregnane steroids and pregnenolone sulfate (PS) are GABAA-receptor antagonists and induce activation-dependent inhibition of the receptor. The activities of neurosteroid are dependent on brain regions and types of neurons. In addition to the slow genomic action of the parent steroids, the non-genomic, and rapid actions of neurosteroids play a significant role in the GABAA-receptor function and shift in mood and memory function. This review describes molecular mechanisms underlying neurosteroid action on the GABAA-receptor, mood changes, and cognitive functions.

  • 24.
    Wang, Ming-De
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Borra, Vijaya Bhaskar
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Strömberg, Jessica
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Lundgren, Per
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Haage, David
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Neurosteroids 3beta, 20 (R/S)-pregnandiols decrease offset rate of the GABA-site activation at the recombinant GABA(A) receptor.2008In: Eur J Pharmacol, ISSN 0014-2999, Vol. 586, no 1-3, 67-73 p.Article in journal (Refereed)
  • 25.
    Wang, Mingde
    et al.
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    He, Yejun
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    Eisenman, Lawrence N
    Department of Neurology, Washington University School of Medicine, St. Louis, Missouri.
    Fields, Christopher
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    Zeng, Chun-Min
    Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, Missouri.
    Mathews, Jose
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    Benz, Ann
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    Fu, Tao
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    Zorumski, Erik
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    Steinbach, Joe Henry
    Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri.
    Covey, Douglas F
    Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, Missouri.
    Zorumski, Charles F
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    Mennerick, Steven
    Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.
    3beta-hydroxypregnane steroids are pregnenolone sulfate-like GABA(A) receptor antagonists2002In: Journal of Neuroscience, ISSN 0270-6474, E-ISSN 1529-2401, Vol. 22, no 9, 3366-3375 p.Article in journal (Refereed)
    Abstract [en]

    Endogenous neurosteroids have rapid actions on ion channels, particularly GABA(A) receptors, which are potentiated by nanomolar concentrations of 3alpha-hydroxypregnane neurosteroids. Previous evidence suggests that 3beta-hydroxypregnane steroids may competitively antagonize potentiation induced by their 3alpha diastereomers. Because of the potential importance of antagonists as experimental and clinical tools, we characterized the functional effect of 3beta-hydroxysteroids. Although 3beta-hydroxysteroids reduced the potentiation induced by 3alpha-hydroxysteroids, 3beta-hydroxysteroids acted noncompetitively with respect to potentiating steroids and inhibited the largest degrees of potentiation most effectively. Potentiation by high concentrations of barbiturates was also reduced by 3beta-hydroxysteroids. 3beta-Hydroxysteroids are also direct, noncompetitive GABA(A) receptor antagonists. 3beta-Hydroxysteroids coapplied with GABA significantly inhibited responses to > or =15 microm GABA. The profile of block was similar to that exhibited by sulfated steroids, known blockers of GABA(A) receptors. This direct, noncompetitive effect of 3beta-hydroxysteroids was sufficient to account for the apparent antagonism of potentiating steroids. Mutated receptors exhibiting decreased sensitivity to sulfated steroid block were insensitive to both the direct effects of 3beta-hydroxysteroids on GABA(A) responses and the reduction of potentiating steroid effects. At concentrations that had little effect on GABAergic synaptic currents, 3beta-hydroxysteroids and low concentrations of sulfated steroids significantly reversed the potentiation of synaptic currents induced by 3alpha-hydroxysteroids. We conclude that 3beta-hydroxypregnane steroids are not direct antagonists of potentiating steroids but rather are noncompetitive, likely state-dependent, blockers of GABA(A) receptors. Nevertheless, these steroids may be useful functional blockers of potentiating steroids when used at concentrations that do not affect baseline neurotransmission.

  • 26.
    Wang, Ming-De
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Rahman, Mozibur
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Inga-Maj
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Agonist function of the recombinant alpha 4 beta 3 delta GABAA receptor is dependent on the human and rat variants of the alpha 4-subunit2010In: Clinical and experimental pharmacology & physiology, ISSN 0305-1870, E-ISSN 1440-1681, Vol. 37, no 7, 662-669 p.Article in journal (Refereed)
    Abstract [en]

    1. It is known that the alpha(4)-subunit is likely to occur in the brain predominantly in alpha(4)beta(3)delta receptors at extrasynaptic sites. Recent studies have revealed that the alpha(1)-, alpha(4)-, gamma(2)- and delta-subunits may colocalize extrasynaptically in dentate granule cells of the hippocampus. In the present study, we characterized a series of recombinant GABA(A) receptors containing human (H) and rat (R) alpha(1)/alpha(4)-, beta(2)/beta(3)- and gamma(2S)/delta-subunits in Xenopus oocytes using the two-electrode voltage-clamp technique. 2. Both H alpha(1)beta(3)delta and H alpha(4)beta(3)gamma(2S) receptors were sensitive to activation by GABA and pentobarbital. Contrary to earlier findings that the alpha(4)beta(3)delta combination was more sensitive to agonist action than the alpha(4)beta(3)gamma(2S) receptor, we observed extremely small GABA- and pentobarbital-activated currents at the wild-type H alpha(4)beta(3)delta receptor. However, GABA and pentobarbital activated the wild-type R alpha(4)beta(3)delta receptor with high potency (EC(50) = 0.5 +/- 0.7 and 294 +/- 5 micromol/L, respectively). 3. Substituting the H alpha(4) subunit with R alpha(4) conferred a significant increase in activation on the GABA and pentobarbital site in terms of reduced EC(50) and increased I(max). When the H alpha(4) subunit was combined with the R beta(3) and R delta subunit in a heteropentameric form, the amplitude of GABA- and pentobarbital-activated currents increased significantly compared with the wild-type H alpha(4)beta(3)delta receptor. 4. Thus, the results indicate that the R alpha(4)beta(3)delta, H alpha(1)beta(3)delta and H alpha(4)beta(3)gamma(2S) combinations may contribute to functions of extrasynaptic GABA(A) receptors. The presence of the R alpha(4) subunit at recombinant GABA(A) receptors containing the delta-subunit is a strong determinant of agonist action. The recombinant H alpha(4)beta(3)delta receptor is a less sensitive subunit composition in terms of agonist activation.

  • 27.
    Wang, Ming-De
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Rahman, Mozibur
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Zhu, Di
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Protons inhibit Cl- conductance by direct or allosteric interaction with the GABA-binding site in the rat recombinant alpha(1)beta(2)gamma(2L) and alpha(1)beta(2) GABA(A) receptor2005In: European Journal of Pharmacology, ISSN 0014-2999, E-ISSN 1879-0712, Vol. 528, no 1-3, 1-6 p.Article in journal (Refereed)
    Abstract [en]

    Functional roles of external pH on the Cl- conductance were examined on Xenopus oocytes expressing rat recombinant alpha(1)beta(2)gamma(2L) and alpha(1)beta(2) GABA(A) receptors. Acidic pH inhibited GABA-response in a reversible and concentration-dependent manner, significantly increasing the EC50 without appreciably changing the slope or maximal currents induced by GABA in the alpha(1)beta(2)gamma(2L) and alpha(1)beta(2) receptors. In contrast, protonation did not influence the pentobarbital-gated Currents in the alpha(1)beta(2)gamma(2L) receptors, suggesting that protons do not modulate channel activity by directly affecting the channel gating process. Protons competitively inhibited the bicuculline-induced antagonism on GABA in the alpha(1)beta(2)gamma(2L) receptors. The data support the hypothesis that protons inhibit GABA(A) receptor function by direct or allosteric interaction with the GABA-binding site.

  • 28.
    Wang, Ming-De
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Rahman, Mozibur
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Zhu, Di
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Backström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Pregnenolone sulfate and zinc inhibit recombinant rat GABAA receptor through different channel property2006In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 188, no 3/4, 153-163 p.Article in journal (Refereed)
  • 29.
    Wang, Ming-De
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Rahman, Mozibur
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Zhu, Di
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Johansson, Inga-Maj
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    3Beta-hydroxysteroids and pregnenolone sulfate inhibit recombinant rat GABA(A) receptor through different channel property.2007In: European Journal of Pharmacology, ISSN 0014-2999, E-ISSN 1879-0712, Vol. 557, no 2-3, 124-131 p.Article in journal (Refereed)
1 - 29 of 29
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf