Effects of lead exposure on sperm toxicity and levels of sexual hormone in sera of male Rana nigromaculata
铅暴露对雄性黑斑蛙精子毒性和血清性激素水平的影响

To evalutate the effects of lead (Pb) exposure on sperm toxicity and levels of sexual hormone in sera of male Rana nigromaculata and to explore the mechanism of lead on male reproductive toxicity, healthy adult male frogs were exposed to 0.1, 0.2, 0.4, 0.8 and 1.6 mg·L-1 of lead solution for 30 days under experimental conditions. The sperm quantity, sperm activity and sperm deformity of the frogs were recorded and analyzed, and the levels of testosterone (T) and estradiol (E2) in sera were measured by enzyme linked immunosorbent assay (ELISA). The results showed that the sperm quantity decreased as Pb concentration increased, and Pb caused an increase in percentage of sperms with deformity and a decrease in sperm motility in a dose-dependent manner. In addition, the T level of sera reduced while the E2 level increased significantly with Pb concentration, displaying an obvious concentration-effect relationship. These results show that Pb has obvious reproductive toxicity on male Rana nigromaculata and can change the testosterone and estradiol levels, and interfere with the reproductive endocrine systems.