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Environmental pollution by heavy metals (HMs) is an increasingly critical problem that is posing a growing threat to reproductive health. Consequently, the aim of the current research was to study changes in rat uterus under 90 days of HMs exposure and estimate the efficacy and benefits of vitamin E treatment. Female rats were randomly divided into three groups: untreated animals (control group); animals orally treated with the HMs mixture (HM group); and animals treated simultaneously with HMs and vitamin E (HM+E group). The toxic effects of the HMs (comprising Zn, Cu, Mn, Fe, Pb, and Cr) on the uterus of rats were investigated by histological, morphometrical, spectrophotometrical, and statistical methods.

Long-term HMs exposure triggered pathological (degenerative, inflammation, and atrophic) changes in the rat uterus together with a significant reduction of the uterine-wall thickness (37.99%, p<0.0001) compared to the control. In contrast, there was a lower intensity of morphological lesions and wall thickness decrease (26.03%, p<0.0001) in the uterus, in rats that underwent treatment with vitamin E. A substantial bioaccumulation of zinc, copper, manganese, iron, lead, and chromium general levels in the rat uterus was demonstrated in both the HM group (74.46%, p<0.0001) and the HM+E group (49.81%, p<0.0001), as compared to the control group. The lowest accumulative potential belonged to Zn and the highest to Pb. The results obtained showed a significant decline in the weight of animals treated by HMs in both HM (18,21%, p<0.01) and HM+E (13,09%; p<0.05) groups compared to the control. Our findings have demonstrated that treatment with vitamin E in HM-induced intoxication has a significant restrain of HMs accumulation (up to 16.46%, p<0.0001) together with morphometric variations (less on 16.17%, p<0.01).

In summary, long-term exposure to the HMs mixture had a pernicious toxic effect on the morphology and chemical content of the uterus of rats (strong negative correlations). Treatment with vitamin E significantly reversed the HMs impact on the uterus but did not demonstrate absolute protection.