2型糖尿病阴虚证小鼠模型生物节律变化及六味地黄汤对其影响

Biological Rhythm Changes of Type-2-diabetic Mice Model with Yin Deficiency Syndrome and the Effect of Liuwei Dihuang Decoction

目的探究2型糖尿病阴虚证“潮热”症状的潜在机制。方法将99只空腹血糖≥16.7 mmol·L^(-1)的8周龄db/db小鼠分为2型糖尿病组、2型糖尿病阴虚证组、2型糖尿病六味地黄汤低、中、高剂量组、2型糖尿病阴虚证六味地黄汤低、中、高剂量组,21只同窝野生对照型雄性m/m小鼠分为空白对照组、阴虚证组。采用“热盛伤阴”法造模,4周后评价小鼠阴虚证表现。后予六味地黄汤组对应剂量灌胃,连续4周。实验期间,每周1次于8:30、15:00,20:00测定小鼠肛温、心前区温度、四肢爪心温度。采用Western blot法观察下丘脑、肝脏生物节律相关蛋白表达情况。结果实验研究表明运用热盛伤阴法可建立2型糖尿病阴虚证模型,其肛温、双上肢爪心温度呈8:30“低”、15:00“高”、20:00“低”的节律变化,六味地黄汤以方测证可见高剂量组能够有效恢复体温节律。下丘脑和肝脏共同可见节律因子Clock、Cry2蛋白表达升高;节律调控中枢下丘脑中,Per2和Cry2蛋白升高明显;在外周靶器官肝脏中,Bmal1、Per3和Cry1蛋白表达升高更显著。结论肝脏和下丘脑生物节律蛋白表达异常可能是导致2型糖尿病阴虚证“潮热”证候特征的重要机制之一。

Objective To explore the potential mechanism of"hot flashes"in mice with type 2 diabetes with yin deficiency syndrome.Methods Ninety-nine 8-week-old db/db mice with fasting blood glucose≥16.7 mmol·L^(-1) were divided into yin deficiency syndrome group,type 2 diabetes group,type 2 diabetes with yin deficiency syndrome group,type 2 diabetes with Liuwei Dihuang Decoction low,medium,high-dose group,type 2 diabetes with yin-deficiency syndrome and Liuwei Dihuang Decoction low,middle,high-dose groups,21 littermates of wild control male m/m mice were control group.The model was established by the method of"heat engenders yin deficiency",and the performance of yin deficiency syndrome in mice was evaluated after 4 weeks.Afterwards,the corresponding doses of Liuwei Dihuang Decoction group were given by gavage for 4 weeks.During the experiment,the rectal temperature,the temperature of the precordial area,and the temperature of the limbs and paws were measured once a week at 8:30,15:00,and 20:00.Western blot was used to observe the expression of biological rhythm-related proteins in the hypothalamus and liver.Results The experimental study showed that the yin deficiency syndrome model of type 2 diabetes could be established by using the method of overheating and injuring the yin.The rhythm changes of Liuwei Dihuang Decoction showed that the high-dose group could effectively restore the body temperature rhythm.The expression of rhythm factors Clock and Cry2 increased in both the hypothalamus and liver;in the hypothalamus,the central rhythm regulation center,the expressions of Per2 and Cry2 increased significantly;in the peripheral target organ liver,the expressions of Bmal1,Per3 and Cry1 increased more significantly.Conclusion The abnormal expression of biological rhythm protein in the liver and hypothalamus may be one of the important mechanisms leading to the characteristics of"hot flashes"in type 2 diabetes with yin deficiency.