实验性2型糖尿病大鼠睾丸Leydig细胞形态和睾酮合成功能的改变

目的：研究糖尿病时睾丸的组织病理学变化及睾丸间质细胞（Leydig细胞）睾酮合成功能的改变。方法：雄性成年SD大鼠20只，随机分为正常对照组10只、糖尿病组10只。后一组给以高脂饮食加小剂量（25mg／kg）链脲佐菌素（STZ）诱导2型糖尿病大鼠模型，12周后处死。用光镜及电镜观察大鼠睾丸的组织形态学改变；逆转录-PCR法检测睾丸组织类固醇激素合成灵敏调节蛋白（steroidogenic acute regulatory proteins，StAR）、胆固醇侧链裂解酶（P450scc）及17a-羟基化酶／17，20-裂解酶（P450c17）mRNA含量；酶联免疫吸附法测定血清中睾酮和黄体生成素（leutelnizing hormone，LH）含量。结果：糖尿病大鼠光镜下主要表现为Leydig细胞数量减少，体积变小：透射电镜下主要见到Leydig细胞萎缩：睾丸组织的StAR mRNA和P450scc mRNA含量糖尿病组低于正常对照组（P〈0．05），P450c17含量糖尿病组较正常对照组差异无显著性（P〉0．05）；与正常对照组相比血清中睾酮和LH含量降低（P〈0．05）。结论：成年期2型糖尿病可以引起大鼠睾丸Leydig细胞功能降低，形态结构改变。

Research on the changes of morphology of testicular Leydig cell and the synthesized function of testosterone in the experimental type-2 diabetic rats

Objective: To study the pathological changes of testis and the changes of the synthesis funelion of testosterone of Leydig cells in type 2 diabetic rats. Methods: Twenty male Sprague-Dauley rats were divided into two groups randomly: normal control group and type 2 diabetic group. Morphological changes of the Leydig cells in both groups were observed under the light microscope (LM) and transmission electron microscopy (TEM). Concentration of blood luteinizing hormone (LH) and testosterone (T) were assayed with the technique of enzyme linked immunosorbent assay (ELISA). Expression of steroidogenic acute regulatory protein (StAR) mRNA, cytochrome P450 side chain cleavage (P450scc) mRNA, and cytochrome P450 17a-hydroxylase (P450c17) mRNA from Leydig cells were examined with RT-PCR respectively. Results: Compared to normal group,the number of Leydig cells decreased under LM and the volume of Leydig cells shrinked under TEM. The level of blood LH and T decreased,the mRNA expression of StAR,P450scc decreased, and the expression of P450c17 mRNA appeared descendent tendency but had no significance in type 2 diabetic group. Conclusion: Type 2 diabetes mellitus impairs T synthesis and the construction of Leydig cells.