Objective   To study the effects of acute cadmium loading on lipid peroxidation reaction and antioxidant enzyme activity of testis in male rat.

  Methods   Thirty six healthy sprague-Dawley(SD)male rats wqere chosen and randomly divided into control group(group C), cadmium-exposure group of middle dose(group M)and cadmium-exposure group of high dose(group H).Group C, M and H were injected by abdominal cavity on every other day with 0, 0.5 and 1.0 mg/kg·bw of cadmium over seven days.Six rats of each group were killed at the 4th day and the 7th day after cadmium exposure and their testis were collected and used in determining activities of glutathion peroxidase(GSH-Px), superoxide dismutase (SOD), peroxidase(CAT), acide phosphatase(ACP), akaline phosphatase(ALP)and lactic dehydrogenase(LDH)as well as contents of malonic aldehyde(MDA)and nitric oxide(NO)in testis tissue homogenate.

  Results   There were no obvious changes of GSH-Px, SOD, CAT, ACP, AL P, LDH and MDA in group M and of GSH-Px, SOD in group H compared with group C, but CAT and MDA in group H were much higher than that in group C at the 4th day of cadmium exposure.At the 7th day after treatment with CdCl2, GSH-Px, SOD, CAT and MDA increased markedly in group M, CAT and MDA level in group H rose significantly, however, GSH-Px and SOD had no obvious changes in the same groups.NO levels of group M and H were higher or much higher than those of group C.During whole experimental period, ACP acitivity in group H was much lower than that in group C and the same change of ALP was found only at the 7th day, ACP and LDH in group M decreased and increased markedly only at the 7th day, respectively, and no obvious difference of ALP was observed compared with group C.

  Conclusion   The antioxidant system of rat's testis was induced by acute cadmium-exposure and participated in mechanism of toxicity damage.The mass release of NO may play an important role in the process of functional activity obstacle of multiple system organs resulting from cadmium.