Study on the reproductive toxicity of subacute cadmium exposure in male Rana nigromaculata

To study the reproductive toxicity and mechanisms of subacute cadmium exposure in male Rana nigromaculata,healthy adult male frogs were exposed to 2.5,5.0,7.5 and 10.0 mg·L-1 of cadmium solution for 14 days under controlled conditions.The sperm quantity and sperm deformity of the frogs were recorded and analyzed,and the ACP,LDH,MDA,GSH,SOD,CAT and GSH-Px contents or activities in the testis of the male frogs were determined.The results showed: ① Cadmium caused a decrease in the sperm quantity and an increase in percentage of deformed sperm in a dose-dependent manner;②Testicular ACP activity decreased(p0.05) at a dosage of 5.0 to 10.0 mg·L-1 while LDH activity decreased(p0.05) at a dosage of 7.5 to 10.0 mg·L-1;③Testicular MDA and GSH contents increased(p0.05) at dosages of 7.5 to 10.0 mg·L-1 while GSH-Px activities decreased(p0.05) at dosages of 7.5 to 10.0 mg·L-1.These results suggest that subacute cadmium exposure is toxic to the reproductive systems of male frogs,and the mechanisms may relate to the decreased activities of certain testicular enzymes and the increased lipid peroxidation,so more attention should be given to the effects of heavy metals on reproductive toxicity in amphibians.