Abstract：Objective To study the effects of manganese exposure on serum sex hormone secretion in male mice. Methods Forty-eight Kunming male mice were randomly divided into the control group and the low-, medium- and high-dose MnCl2-treated groups. The control group was intraperitoneally injected with saline, while the low-, medium- and high-dose MnCl2-treated groups were intraperitoneally injected with 12.5 mg/kg, 25 mg/kg and 50 mg/kg respectively. All administration was given at a dose of 5 ml/kg body weight per mouse per day for fourteen consecutive days. All the mice were sacrified 24 hours after the final injection, and indexes of body weight, testis and epididymis were tested. The collected abdominal aortic blood was centrifugated, and the serum levels of gonadotropin-releasing hormone (GnRH), folide-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T) were detected by ELISA kit. HE staining was performed to observe the morphologic changes of hypothalamus neurons. Results No statistically significant differences were found in the body weight and organ coefficients of testis and epididymis between the control group and each MnCl2-treated group (P>0.05). The serum levels of GnRH, FSH and LH in the high-dose MnCl2-treated group were significantly increased to 68.22 ng/L, 11.43 U/L and 2,055.82 pg/ml respectively (P<0.05), while the T level was significantly declined to 81.25 nmol/L(P<0.05). HE staining revealed that the control group had clear structure, regular arrangement and clear nuclear membrane, while the MnCl2-treated groups gradually appeared morphological disorder, the shrunken cell body and the increased space around the cells. Conclusions Exposure to manganese can cause abnormal serum hormone secretion and impaired hypothalamic morphology in male mice. The serum levels of GnRH, FSH and LH are significantly increased, while the serum level of testosterone is decreased.
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2019, Vol. 26 
