大黄对糖尿病大鼠血管病变保护机制的研究

目的:探讨大黄对糖尿病血管病变的保护机制。方法:制备糖尿病大鼠模型,成模后,随机抽取24只分为模型组(12只)及大黄煎剂组(12只),另取12只不造模大鼠为正常组。大黄煎剂组给予生药10 g.kg^-1灌胃,其余两组每日给予同等容量纯净水灌胃。8周后,取血测定一氧化氮(NO)及内皮素-1(ET-1)。取胸主动脉环观察不同累积浓度的乙酰胆碱(Ach)对去甲肾上腺素(NE)引起的血管收缩的抑制率。另留取一段胸主动脉制备病理切片,SP法免疫组化染色,观察细胞间黏附分子-1(ICAM-1)及血管细胞间黏附分子-1(VCAM-1)的阳性表达。结果:大黄煎剂组与模型组相比能明显抑制升高的血浆ET-1(P<0.05);升高NO的水平(P<0.05);但均达不到正常组的水平(P<0.05)。模型组血管环对NE的收缩反应明显强于正常组及大黄煎剂组(P<0.05),且大黄煎剂组对NE的收缩反应亦强于正常组(P<0.05)。在相同Ach浓度下,模型组及大黄煎剂组胸主动脉环对Ach的舒张作用明显弱于正常组(P<0.05),而大黄煎剂组强于模型组(P<0.05)。大黄煎剂组能明显抑制糖尿病大鼠胸主动脉ICAM-1及VCAM-1表达(P<0.05)。结论:大黄具有降低大鼠ET-1及升高NO的作用,能够保护糖尿病大鼠内皮依赖的血管舒张功能,且能够抑制ICAM-1及VCAM-1的表达,具有抗动脉硬化作用。

Protective mechanism on the vascular pathological process in diabetes mellitus rats by Rheum officeinale

OBJECTIVE: To explore the protective mechanism of officeihale on the vascular pathological process in diabetes mellitus (DM) rats. METHOD: After the DM rat model was established, 24 DM rats were randomly divided into model group (12 DM rats) and Rheum officeinale group (12 DM rats). Rheum officeinale was orally given in 10 g kg(-1) per day, and the other two groups were given equal pure water. 8 weeks later, blood samples were collected to determine the level of nitric oxide (NO) and endothelin-1 (ET-1). Thoracic aortic rings was prepared to observe the inhibiting effect of Ach with different concentration on contraction caused by NE. Another part of aorta was made to observe the expression of ICAM-1 and VCAM-1 by method of SP immunohistochemistry staining, RESULT: Rheum officeinale group obviously decreased the level of ET-1 and increased the NO compared with model group (P <0.05). The expression of ICAM-1 and VCAM-1 could be obviously inhibited in Rheum officeinale group compared with model group. (P <0.05). CONCLUSION: Rheum officeinale could decrease the level of ET-1 with increased the NO in diabetes rats, and inhibit the expression of ICAM-1 and VCAM-1, which may be mechanisms of protecting the endothelium of vessel in diabetes rats.