OBJECTIVETo investigate the effects of nanosized cadmium sulfide (nano-CdS) on the male reproductive system in mice.

METHODSThirty-six specific pathogen?free male ICR mice were equally and randomly divided into three groups: two experimental groups and a control group. The two experimental groups were exposed to 100 mg/kg and 50 mg/kg nano-CdS once daily by gavage, respectively, while the control group was exposed to the same volume of physiological saline once daily by gavage. After 45 days, levels of cadmium accumulation and serum testosterone in the testis were determined, the epididymal sperm count, the rate of sperm abnormality, and histopathological changes in testis tissue were observed under a microscope, and the level of CYP11A1 mRNA was determined by qRT-PCR.

RESULTSCompared with the control group, the two experimental groups had a significantly increased level of cadmium accumulation in the testis (P < 0.05), and the 100 mg/kg nano-CdS group had a significantly decreased epididymal sperm count (P < 0.05) and a significantly increased rate of sperm abnormality (P < 0.05), but the 50 mg/kg nano-CdS group did not. The 100 mg/kg nano-CdS group showed different histopathological changes in testis tissue, but the 50 mg/kg nano-CdS group did not. The two experimental groups had significantly reduced levels of testosterone and CYP11A1 mRNA compared with the control group.

CONCLUSIONNano-CdS given through the digestive tract may have an effect on the male reproductive system in mice by affecting the key enzyme genes in the androgen synthesis pathway to reduce the levels of reproductive hormones.