Abstract: 【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), 1 μg/100 μL GnIH (group Ⅰ) and 10 μg/100 μL GnIH (group Ⅱ), 12 rats in each group with half male and half female.Saline or GnIH (200 μL 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-α and IL-1β were 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 group Ⅰ and male SD rats in group Ⅱ was increased significantly, the ovarian size/weight and ovary-to-body ratio of group Ⅱ were 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 group Ⅱ showed cystic expansion, the granulosa cell layer decreased and the follicular cavity became larger.The spermatogenic tubules of male rats in groups Ⅰ and Ⅱ were vacuolated, and spermatogenic cells were disordered and their levels decreased.Compared with control group, the proestrus period of rats in group Ⅱ was 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 group Ⅰ and group Ⅱ were extremely significantly decreased (P<0.01), the expression of IR gene of group Ⅱ was significantly decreased (P<0.05), the expression of GLUT4 gene in male rats of groups Ⅰ and Ⅱ was significantly decreased (P<0.01), the expressions TNF-α and IL-1β genes of female and male rats in group Ⅰ were increased significantly (P<0.05), the expression of TNF-α gene in female and male rats of group Ⅱ was 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.

Key words: rats; gonadotropin-inhibitory hormone; glucose metabolism; ovary; testis; correlation analysis