孕期高雄激素法构建多囊卵巢综合征模型大鼠卵巢内胰岛素信号分子的表达

目的 使孕中期雌鼠暴露于高雄激素状态,观察其雌性子代成年后的生殖与代谢状况,构建多囊卵巢综合征（PCOS）大鼠模型.方法 Wistar雌性大鼠,在孕16～18 d颈背部皮下注射丙酸睾丸酮,连续3 d.以其所生雌鼠长至成年作为实验对象,观察其体重及动情周期,并检测血清性激素,17-羟孕酮（17-OHP）、雄烯二酮（A2）及口服葡萄糖耐量试验（OGTT）测血糖、胰岛素水平,评估胰岛素抵抗;运用免疫组化及蛋白印迹方法,检测卵巢组织中胰岛素受体底物（IRS-1、-2）、磷脂酰肌醇3激酶（PI-3K P85）、葡萄糖转运蛋白4（GLUT4）、细胞外信号调节激酶（ERK-1）、17α-羟化酶（CYP17）等蛋白的表达.结果 （1）孕中期雌鼠给予雄激素处理后,其所生雌鼠无明显动情周期,卵巢多囊样改变,睾酮、17-OHP和A2水平明显升高（P〈0.05）;OGTT试验2 h血糖升高（P〈0.05）;葡萄糖曲线下面积增高（P=0.065）;空腹胰岛素水平显著升高（P〈0.05）;OGTT试验0.5 h胰岛素升高（P=0.068）;稳态模型评估（HOMA）指数升高（P〈0.05）.（2）Western blot结果显示模型大鼠卵巢组织IRS-1、IRS-2、PI-3KP85、GLUT4均呈低表达,ERK1、CYP17均呈高表达.结论 给孕中期雌鼠注射丙酸睾丸酮,所生雌鼠表现无排卵、高雄激素血症、胰岛素抵抗、糖耐量低减,符合人类PCOS特征,可以作为PCOS动物模型.卵巢局部胰岛素信号传导蛋白的表达异常.

Expression of ovary insulin signaling molecules in polycystic ovary syndrome rat model constructed by prenatal androgenization

Objective： To construct polycystic ovary syndrome rat model by maternal exposure to excess testosterone and examine the reproduction and metabolism in the rat models. Methods. On days 16-18 of pregnancy, Wistar female rats were injected s. c. with testosterone propionas 2. 50 mg/0. 10 ml or sesame oil daily for 3 consecutive days. Adult female offsprings were studied. Body weight and estrous cycles were observed. Serum concentrations of sex hormones, 17ahydroxy progesterone （17-OHP）, androstenedione （A2）, insulin and glucose during oral glucose tolerance test （OGTT） were measured. Insulin signaling molecules including insulin receptor substrate-1 （IRS-1） and 2 （IRS-2）, phosphatidylinositol-3 kinase P85a （PI-3K P85a）, glucose transporter-4 （GLUT4）, extracellular signal regulated kinase-1 （ERK-1）, 17a-hydroxylase （CYP17） protein expression in ovary were determined by immunohistochemistry and Western blot. Results： （1）The female rats that were prenatally androgenized had irregular estrous cycles and polycystic ovary. Serum levels of testosterone, 17-OHP and A2 were significantly higher than those in control group （P〈0.05）, and glucose level at 2h during OGTT, fasting insulin level, and HOMA-IR were elevated significantly （P〈0.05）. The insulin levels at 0.5 h during OGTT and area under curve （AUC） of glucose in the rat models were increased, but without significant difference （P=0. 068 and P= 0. 065, respectively）. （2） Western blot showed that the expressions of IRS-1, IRS-2, PI-3KP85a and GLUT4 in model ovarian tissues were lower, and the expression of ERK1 and CYP17 were higher than in control. Conclusions： Prenatally androgenized female rats exhibited anovulation, hyperandrogenism, insulin resistance and decreased glucose tolerance, which is coincident with the characteristics of human PCOS. The model rats exhibited abnormal expression of insulin signaling transduction molecules in ovarian tissues.