镉对大鼠睾丸间质细胞损伤及锌对其保护的形态学研究

Morphological Study of Injurious Action of Cadmium and Protection of Zinc on Rat Leydig Cells

用透射电镜和葡萄糖６ 磷酸酶（Ｇ ６ Ｐａｓｅ）电镜细胞化学定量技术，观察小剂量氯化镉（２ ｍ ｇ／ｋｇ 体重）腹腔内注射后１ ｈ 至６０ｄ 大鼠睾丸间质细胞超微结构与Ｇ ６ Ｐａｓｅ活性改变及锌对其的保护作用。镉注射４ ｈ 后滑面内质网（ＳＥＲ）扩张，脂滴增多，髓样结构形成，部分毛细淋巴管及毛细血管内皮胞质出现空泡；２４ ｈ 后脂滴进一步增多，体积增大，少数细胞核固缩和胞质溶解；３～１５ ｄ 上述损伤继续加重，线粒体基质有絮状沉积物；３０ ｄ 后退变减轻；６０ ｄ 后间质内纤维成份显著增多，大部分睾丸间质细胞超微结构仍呈退变。镉注射１ ｈ 后内质网Ｇ ６ Ｐａｓｅ 反应产物下降；２４ ｈ 后明显减少；３～１５ ｄ 减少最显著；３０ ｄ 有较明显恢复。锌保护各组较对应单纯镉组超微结构损伤显著为轻，其Ｇ ６Ｐａｓｅ 反应产物亦明显多于相应单纯镉组。结果表明小剂量镉对睾丸间质细胞超微结构和Ｇ ６ Ｐａｓｅ 活性有早期直接损伤，且酶活性改变早于超微结构变化。毛细淋巴管及毛细血管损伤及间质纤维增生进一步加重损伤改变。锌则具有明显保护作用。

The Wistar rats were injected with lowdose CdCl 2 (2 mg/kg body weight). The specimens obtained from 1 hour to 60 days after dosing were studied by using transmission electron microscope combined with a quantitative analysis of glucose6phosphatase (G6Pase) cytochemistry. Meanwhile, the protective effects of Zn on Cdinduced injury were observed. The ultrastructural changes of Leydig cells (LCs) were detected at the 4th hour hours after Cd treatment and became more serious after 24 hours. The main alterations were dilatation of smooth endoplasmic reticulum, the increase of lipid droplets and myelin figures as well as appearance of vaculoes in the endothelial cell of lymphatic and blood capillaries. At the 3rd,7th and 15th day, the degeneration above mentioned was most prominent, and numerous necrotic LCs and flocculent densities in mitochondria were seen. After 30 days, the injury of LCs appeared to be alleviated. But most of LCs were still not recovered after 60 days. In addition, the G6Pase reaction products reduced at 1 hour after Cd treatment, and such decrease was most pronounced within 3～15 days. After 30 days, there was an obviously recovery of the G6Pase reaction products. The injury of LCs of Zn protected groups was gentle and the G6Pase reaction products were more than those in Cd treated groups at the same time. The results showed that the early injury of LCs was related to the direct action of Cd; the effects of Cd on the G6Pase activities were earlier than the morphological alterations; the damage of lymphatic and blood capillaries as well as interstitial fibrosis might accelerate the degeneration; Zn could protect LCs obviously from being damaged by Cd. $$$$