丝胶预处理对糖尿病大鼠睾丸IGF-1表达的影响

目的探讨丝胶预处理对2型糖尿病大鼠睾丸胰岛素样生长因子-1(insulin-like growth factor-1,IGF-1)表达的影响。方法 30只雄性SD大鼠随机分为3组(n=10):正常对照组、糖尿病模型组和丝胶预处理组。链脲佐菌素连续腹腔注射制作2型糖尿病大鼠模型,以血糖≥16.7mmol/L作为成模标准;丝胶预处理组大鼠在注射链脲佐菌素前给予丝胶灌胃(2.4g/kg/d)35d。采用葡萄糖氧化酶法检测血糖,采用ELISA方法检测大鼠血清睾酮和IGF-1水平;分别采用免疫组化染色和RT-PCR法检测睾丸IGF-1蛋白和mRNA的表达。结果丝胶预处理可明显抑制糖尿病大鼠血糖升高,血清睾酮、IGF-1水平的降低,睾丸IGF-1表达的下降(丝胶预处理组与糖尿病模型组比较:P0.01)。结果 丝胶预处理可通过阻止糖尿病大鼠睾丸IGF-1表达的下调,改善生精功能,发挥对糖尿病生殖功能损害的预防保护作用。

EFFECTS OF SERICINE PRETREATMENT ON IGF-1 EXPRESSION IN TESTES OF DIABETES MELLITUS RAT MODEL

Objective To study the effects of sericine pretreatment on the expression of insulin-like growth factor-1（IGF-1） in testes of type 2 diabetes mellitus rat model.Methods 30 male SD rats were randomly divided into 3 groups（n=10）： normal control group,diabetes model group and sericine pretreatment group.The type 2 diabetes model was induced by continuous intraperitoneal injection of streptozotocin,and blood glucose≥16.7mmol/L was taken as standard.The rats in sericine pretreatment group were lavaged with sericine（2.4g/kg/d） for 35 days before injecting streptozotocin.Glucose oxidase method was used to detect blood glucose of rats in each group,ELISA was used to detect testosterone and IGF-1 level in the serum,immunohistochemical staining and RT-PCR were respectively used to detect the expression of IGF-1 protein and mRNA in testes.Results Sericine pretreatment significantly inhibited increasing of blood glucose,decreasing of testosterone and of IGF-1 level in the serum,and inhibited descending of IGF-1 expression in testes（sericine pretreatment group compared with model group： P0.01）.Conclusion Sericine pretreatment has preventive effects on reproductive dysfunction of diabetic rats,improving the spermatogenic function by preventing the down-regulation of IGF-1 expression in testes.