左归降糖解郁方对糖尿病并发抑郁症大鼠下丘脑信号通路的影响

Effect of Zuogui Jiangtang Jieyu Formulation on Signaling Pathway in Hypothalamus of Diabetic Rats with Depression

目的研究左归降糖解郁方对糖尿病并发抑郁症大鼠下丘脑sigma-1受体/蛋白激酶C(sigma-1 receptor/protein kinase C,sigma-1R/PKC)信号通路的影响。方法建立糖尿病并发抑郁症的动物模型,并随机分为4组:模型组、阳性药组、左归降糖解郁方高剂量组(20.53 g·kg-1)、左归降糖解郁方低剂量组(10.26 g·kg^-1),另设健康SD大鼠为正常组。灌胃给药28 d后,各组大鼠尾静脉取血检测血糖含量,开野试验检测大鼠的自主活动能力,HE染色检测大鼠下丘脑的病理损伤情况,ELISA法检测大鼠下丘脑匀浆液中促肾上腺皮质激素释放因子(corticotropin releasing factor,CRF)含量,Western-blot法检测大鼠下丘脑中sigma-1R蛋白表达以及PKC,糖皮质激素受体(glucocorticoid receptor,GR)蛋白的磷酸化水平。结果与正常组比较,模型组大鼠血糖含量显著升高而活动能力显著减弱(P<0.01),下丘脑中CRF含量显著升高(P<0.05)而sigma-1R的表达以及p-PKC/PKC,p-GR/GR比值显著降低(P<0.05或P<0.01)。与模型组比较,左归降糖解郁方高剂量组大鼠血糖含量显著降低(P<0.05),活动能力增强(P<0.01),下丘脑中CRF含量显著降低而sigma-1R,p-PKC/PKC,p-GR/GR显著升高(P<0.05或P<0.01)。结论高剂量左归降糖解郁方可有效调节sigma-1R水平,并通过激活sigma-1R/PKC信号通路,降低模型大鼠下丘脑中CRF的含量,从而发挥降血糖和抗抑郁的双重作用。

OBJECTIVE To investigate the effect of Zuogui Jiangtang Jieyu formulation on sigma-1 receptor/protein kinase C(sigma-1 R/PKC) signaling pathway in hypothalamus of diabetic rats with depression. METHODS Animal models of diabetes complicated with depression were established and randomly divided into 4 groups: model group, positive drug group,high and low dose of Zuogui Jiangtang Jieyu formulation group(20.53, 10.26 g·kg^-1). Additionally, the normal rats were belongs to the normal group. After 28 d of intragastric administration, blood glucose in each group was detected. Then the open field test was used to test the autonomic activity of rats. The pathological damage of hypothalamus was detected by HE staining in each group, and the content of corticotropin releasing factor(CRF) in hypothalamus homogenate of rats was detected by ELISA. At last, expression levels of sigma-1 R, phosphorylation of PKC and glucocorticoid receptor(GR) in hypothalamus were evaluated by Western-blot. RESULTS Compared with the normal group, the blood glucose level was significantly increased and the activities were significantly decreased in model group(P<0.01). The level of CRF in hypothalamus was significantly increased(P<0.05), while the expression of sigma-1 R, p-PKC/PKC, and p-GR/GR were significantly decreased(P<0.05 or P<0.01). Compared with the model group, high dose of Zuogui Jiangtang Jieyu formulation administration rescued the reduction in blood glucose(P<0.05) and improved activities(P<0.01), which in turn reduced the level of CRF in hypothalamus(P<0.05).Furthermore, the high dose of this formulation treatment also increased the expression of sigma-1 R, p-PKC/PKC, and p-GR/GR(P<0.05 or P<0.01). CONCLUSION High dose of Zuogui Jiangtang Jieyu formulation can effectively regulate the expression level of sigma-1 R, and reduce the content of CRF in hypothalamus by activating sigma-1 R/PKC signaling pathway.The above mechanism of this formulation may be related to the effect of hypoglycemic and antidepressant.