镉对大鼠附睾体部的损伤及锌的保护作用

THE INJURIOUS EFFECTS OF CADMIUM ON EPIDIDYMAL CORPUS AND THE PROTECTIVE EFFECTS OF ZINC IN RATS

目的探讨镉对大鼠附睾体部的超微结构影响及其作用机理。方法单纯小剂量氯化镉（２ｍｇ／ｋｇ体重）及加锌腹腔内注射后，用透射电镜及硫胺素焦磷酸酶（ＴＰＰａｓｅ）电镜细胞化学定量分析。结果镉注射后４ｈ，主细胞出现轻度超微结构损伤；２４ｈ至３ｄ进一步加重；７～１５ｄ退变最严重；３０～６０ｄ基本恢复。ＴＰＰａｓｅ反应产物４ｈ后明显减少，３ｄ后暂时回复，但７～１５ｄ再次下降，６０ｄ恢复正常。锌保护各组主细胞形态正常，ＴＰＰａｓｅ反应产物较单纯镉组量多，至１５ｄ达正常水平。结论镉对大鼠附睾体部的损伤较轻；镉对主细胞ＴＰＰａｓｅ活性的影响比对结构的损伤敏感些；早期损伤系镉的直接毒理作用，后期则由于雄激素水平下降加重损伤。

Objective\ Investigating the effects of cadmium(Cd) on the ultrastructural changes of epididymal corpus and the protective effects of zinc. Methods\ The animals were injected with small dose of CdCl 2(2mg/kg body weight) and Cd+Zn.The specimens were studied with transmission electron microscope and quantitative analysis of thiamine pyrophosphatase(TPPase) cytochemistry. Results\ The injures of principal cells could be detected after 4 hours of Cd treatment and became more serious within 24 hours to 3 days.The degeneration was most prominent within 7～15days, but tended to alleviate after 30～60 days.The TPPase reactive product was reduced markedly on the day 4 after Cd treated.There was a temporary recovery of the TPPase reactive product on day 3 but decreased again within 7～15 days.After 60 days of Cd treatment,the TPPase reactive product returned to normal.The morphology of principal cells of Zn protected groups was almost normal,and the quantity of TPPase reactive product was more than that of Cd treated groups at the same time.On day 15,it returned to normal. Conclusions\ The injurious effects of cadmium on epididymal corpus were milder;The effects of cadmium on the TPPase activity were more sensitive than the morphological alterations;The earlier damage of epididymal corpus was related to the direct action of cadmium;The decrease of androgen at the later stages might accelerate the degeneration.