| Objective: Cadmium, one of the most of dangerous heavy metals, had been proved to have toxic effects to several kinds of organs and tissues of laboratory animals and human beings, especially male reproductive system, which was one of the most sensitive tissues to the toxic effects of Cd. It had been demonstrated that various procedures were involved in cadmium-induced reproductive toxicity, such as oxidative stress, inhibition of enzyme activity, interaction between cadmium and calcium, cadmium and MT, cadmium and microelement. Additionally, over-expression of proto-oncogene induced by cadmium was likely contributed to carcinogenesis of cadmium. But few studies were concerned about the prevention on cadmium-induced reproductive toxicity. The objective of this research was to demonstrate whether Compound Cordyceps Sinesis(CCS) could antagonize cadmium-induced male reproductive toxicity, and by which mechanisms it worked. This study was also to provide the evidences to the prevention and treatment of cadmium-induced toxicity.Methods: (1) establish the model of cadmium-induced male reproductive toxicity:16 male Sprague-Dawley rats were randomly divided into two groups: control group and CdCl2 group. CdCl2 animals were injected sc with CdCl2 at a dose of 1 mg/kg body weight once per two days for two weeks; control animals were injected sc withequal saline at the same time. Four weeks after CdCl2 injection all rats were euthanized and one testis was selected to examine the pathology. The same side of epididymises were examined with the quality of sperm. The other testis were examined with LDH-X activity. The standard of male reproductive toxicity was that all targets had obvious significance between two groups and the pathology of testis changed significantly.(2)the selection of prevention materials: Different preventions were studied to against cadmium-induced male reproductive toxicity in the previous researches . Our results showed that CS was so effective that it was selected as the prevention in this study .(3)the prevention of CCS and its mechanism against cadmium-induced male reproductive toxicity: 50 male Sprague-Dawley rats were randomly divided into five groups _control group, CdCl2 group, low-dose CCS group, middle-dose CCS group and high-dose CCS group. Control animals were injected sc with saline, the other groups were injected sc with at a dose of 1mg/kg body weight once per two days for two weeks. At the same time the rats were given with 2.5%, 5%, 10% CCS (1ml/100g) and distilled water once daily for four weeks. After finishing the prevention , all ratswere killed and the targets were measured. All data were expressed as x ±D and were analyzed by Student's t test ,one-way anova and H-Test.Results: (1) CCS could antagonize cadmium-induced male reproductive toxicity: A significant reduction in the weight of the testis , the sperm population , motility and viability of the epididymis were recorded in rats treated with cadmium alone. This was accompanied by an increase of malformed sperm in epididymis. High-dose CCS given resulted in partial recovery of the reproductive parameters studied (P<0.05). Through the pathological examination of the testis we could see that: treatment with CdCl2 resulted in testicular atrophy such as the wall of seminiferous tubule was thinner, the tubule was larger, which had less count sperm as compared to control group. However testes from rats that were treated with CCS appeared to show much lesscadmium-induced damage, especially in high-dose CCS group. (2) The preventive mechanisms of CCS antagonize cadmium-induced male reproductive toxicity: the testicular MDA, Ca, Cd contents and urine Cd concentration were higher in the CdCl2 than in the control group. AS compared to CdCl2 alone group, both low and high-dose CCS could increase urine Cd concentration(P<0.05), high-dose CCS could also partially reverse the increasing testicular MDA and Ca , Cd contents induced by cadmium(P<0.05).Administration of CdCl2 resulted in a reduction in testicular... |
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