促性腺激素抑制激素对SD大鼠性腺生殖功能与糖代谢的影响

Effects of Gonadotropin Inhibitory Hormone on Gonadal Reproductive Function and Glucose Metabolism in SD Rats

【目的】探究促性腺激素抑制激素(GnIH)对SD大鼠性腺生殖功能和糖代谢的影响,以及SD大鼠性腺生殖功能和糖代谢之间的相关性。【方法】将36只SD大鼠随机均分为对照组(0.9%生理盐水)、1μg/100μL GnIH组(Ⅰ组)、10μg/100μL GnIH(Ⅱ组),每组12只(雌雄各半)。每天07:00和19:00注射生理盐水或GnIH(200μL/次),连续注射14 d后测量大鼠体重,计算肥胖程度,麻醉处死后采集卵巢和睾丸,称重并计算卵体比和睾体比;运用阴道涂片法观察雌性大鼠发情周期的变化;显微镜下观察并计算雄性大鼠精子活力;HE染色观察卵巢和睾丸组织变化;用实时荧光定量PCR法检测卵巢和睾丸中糖代谢基因胰岛素受体(IR)、葡萄糖转运蛋白4(GLUT4)和炎症相关因子肿瘤坏死因子(TNF-α)、白介素1β(IL-1β)的表达水平,并用SPSS 22.0软件分析生殖功能和糖代谢之间的相关性。【结果】与对照组相比,Ⅰ组雌性SD大鼠和Ⅱ组雄性SD大鼠肥胖程度均显著升高(P<0.05);Ⅱ组卵巢大小/重量、卵体比显著升高,睾丸重量、睾体比显著下降(P<0.05)。HE染色结果显示,与对照组相比,Ⅱ组雌性大鼠卵泡呈囊性扩张,颗粒细胞层减少,卵泡腔变大;Ⅰ、Ⅱ组雄性大鼠的生精小管均出现空泡样改变,生精细胞排列紊乱、层次减少。与对照组相比,Ⅱ组大鼠发情前期的持续时间显著延长(P<0.05)、精子活力显著下降(P<0.05)。实时荧光定量PCR结果显示,与对照组相比,Ⅰ、Ⅱ组雌性大鼠GLUT4基因的表达量极显著下降(P<0.01)、Ⅱ组中IR基因的表达量显著降低(P<0.05),Ⅰ、Ⅱ组雄性大鼠GLUT4基因的表达量均极显著降低(P<0.01);Ⅰ组雌性大鼠TNF-α、IL-1β基因和雄性大鼠IL-1β基因的表达量均显著升高(P<0.05),Ⅱ组雌、雄大鼠TNF-α基因的表达量均极显著升高(P<0.01)。相关性分析结果显示,腹腔注射GnIH后,雌性大鼠的卵体比与GLUT4基因表达水平呈极显著正相关(P<0.01),与IR基因的表达水平呈显著正相关(P<0.05);雌性大鼠的发情周期与GLUT4基因表达水平呈极显著负相关(P<0.01);雄性大鼠睾体比与GLUT4基因表达水平均呈显著正相关(P<0.05),而精子活力与GLUT4基因表达水平均呈极显著正相关(P<0.01)。【结论】腹腔注射GnIH能够抑制大鼠的生殖功能和导致糖代谢功能紊乱,而且GnIH可能参与性腺能量代谢与生殖功能的交叉对话,是能量代谢与生殖功能的新型联络因子。

【Objective】The purpose of this study was to explore the effect of gonadotropin inhibitory hormone(GnIH)on gonadal reproductive function and glucose metabolism of SD rats,and the correlation between gonadal reproductive function and glucose metabolism of SD rats.【Method】36 SD rats were randomly divided into control group(0.9%normal saline),1μg/100μL GnIH(groupⅠ)and 10μg/100μL GnIH(groupⅡ),12 rats in each group with half male and half female.Saline or GnIH(200μL each time)was injected at 07:00 and 19:00 every day,after 14 days of continuous injection,the weight of rats was measured to calculate the degree of obesity.After death under anesthesia,ovaries and testis were collected,weighed,and the egg body ratio and testis body ratio were calculated.The changes of estrus cycle of female rats were observed by vaginal smear.The sperm motility of male rats was calculated under microscope.HE staining was used to observe the changes of ovarian and testicular tissues.The expression levels of glucose metabolism genes IR and GLUT4 as well as inflammation-related factor genes TNF-αand IL-1βwere detected by Real-time quantitative PCR in ovary and testis of SD rats.The correlation between reproductive function and glucose metabolism was analyzed by SPSS 22.0 software.【Result】Compared with control group,the degree of obesity of female SD rats in groupⅠand male SD rats in groupⅡwas increased significantly,the ovarian size/weight and ovary-to-body ratio of groupⅡwere increased significantly,the testicular weight and testis-to-body ratio was significantly decreased(P<0.05).HE staining results showed that compared with control group,the follicles of female rats in groupⅡshowed cystic expansion,the granulosa cell layer decreased and the follicular cavity became larger.The spermatogenic tubules of male rats in groupsⅠandⅡwere vacuolated,and spermatogenic cells were disordered and their levels decreased.Compared with control group,the proestrus period of rats in groupⅡwas significantly prolonged,the sperm motility was significantly decreased(P<0.05).Real-time quantitative PCR results showed that compared with control group,the expression level of GLUT4 gene in female rats of groupⅠand groupⅡwere extremely significantly decreased(P<0.01),the expression of IR gene of groupⅡwas significantly decreased(P<0.05),the expression of GLUT4 gene in male rats of groupsⅠandⅡwas significantly decreased(P<0.01),the expressions TNF-αand IL-1βgenes of female and male rats in groupⅠwere increased significantly(P<0.05),the expression of TNF-αgene in female and male rats of groupⅡwas significantly increased(P<0.05).The results of correlation analysis showed that the ovary-to-body ratio of female rats was extremely significantly positively correlated with the expression levels of GLUT4 gene(P<0.01),and significantly positively correlated with the expression levels of IR gene(P<0.05),the estrous cycle of female rats was significantly negatively correlated with the expression levels of GLUT4 gene(P<0.01),and the testis-to-body ratio of male rats was significantly positively correlated with the expression levels of GLUT4 gene(P<0.05),while the sperm motility was extremely significantly positively correlated with the expression levels of GLUT4 gene(P<0.01).【Conclusion】Intraperitoneal injection of GnIH could inhibit reproductive function and lead to the disorder of glucose metabolism in rats,and GnIH might participate in the cross-talk between gonadal energy metabolism and reproductive function,was a new connecting factor between energy metabolism and reproductive function.