丝胶对糖尿病大鼠海马生长激素及其受体表达的调节作用

Regulatory effects of sericine on expression of GH and GHR in hippocampus of diabetes mellitus

目的探讨丝胶对2型糖尿病(T2DM)模型大鼠海马生长激素(GH)和生长激素受体(GHR)表达的调控作用。方法将36只雄性SD大鼠随机分为空白对照组、T2DM模型组和丝胶用药组,每组12只。腹腔注射链脲佐菌素制备T2DM大鼠模型;在成功制备模型后,对模型大鼠灌胃给予丝胶(2.4 g·kg^(-1)·d^(-1))35 d。分别检测各组大鼠的血糖和血清GH水平(ELISA法),检测大鼠海马GH、GHR蛋白(蛋白印迹法)和mRNA(逆转录PCR法)的表达情况。结果与空白对照组大鼠比较,T2DM模型组大鼠的血糖、血清GH水平、海马GH的表达明显升高,海马GHR的表达明显降低(P<0.05);与糖尿病模型组相比,丝胶组大鼠的血糖、血清GH水平,GH在海马的表达显著降低,GHR在海马的表达显著升高(P<0.05)。结论丝胶可能通过调节糖尿病时海马GH和GHR的表达,进而改善海马GH-GHR/IGF-1轴的功能。

Objective To explore the regulatory effect of water soluble protein in silk cocoons-sericine on growth hormone （GH） and growth hormone receptor （GHR） expression in hippocampus of type 2 diabetes mellitus rats. Methods A total of 36 SD male rats were divided into 3 groups randomly （n= 12） ： blank, type 2 diabetes mellitus model and sericine groups. Intraperitoneal injection of streptozotocin was used to induce the type 2 diabetic rat model. After successfully prepared the model, the model rats were given the sericine （ 2.4 g · kg^-1 · d^-1） for 35 days intragastrically. The blood glucose, serum GH level was respectively measured by ELISA; as well as the expression of GH, GHR protein and mRNA in hippoeampus of rats were detected by Western blot and reverse transcription polymerase chain reaction （RT-PCR）. Results Compared with blank control group, the blood glucose, serum GH level, GH expression in hippocampus of model group were increased obviously; GHR expression in hippocampus was significantly reduced （P〈0.05）. Compared with model group, the blood glucose, serum GH level, GH expression in hippocampus of sericine group were decreased obviously; GHR expression in hippocampus was increased obviously （ P〈0.05 ）. Conclusions Sericine might improve the function of GH-GHR/IGF-1 axis in hippocampus by regulating the expression of GH and GHR in hippoeampus.