糖尿病大鼠脑小血管内皮P-选择素表达研究

Expression of P-selectin in cerebrovascular endothelial cells of rats with diabetes

目的 探讨糖尿病鼠脑小血管病变机制，方法 利用1％链脲佐菌素（STZ）诱导的糖尿病动物模型，将SD大鼠随机分为正常组、糖尿病病程8周组（DM8组）、糖尿病病程24周组（DM24组）观察糖尿病对鼠脑血管内皮P-选择素（PS）表达的影响和炎性标志物血浆C-反应蛋白（CRP）的动态变化。结果 正常大鼠脑内无PS表达；糖尿病大鼠脑内PS主要表达在直径为7．5～30μm的微血管上糖尿病人鼠PS表达较正常大鼠显著增高（P〈0，01）；随病程延长DM24组的PS表达较DM8组也有显著增加（P〈0．05）造模前各组大鼠的血浆CRP含量无差异，造模后DM8组、DM24组CRP分别为64．7±8．12mg／L和1263±123mg／L，较正常大鼠均有显著增高（P〈0.01），DM24组的较DM8组的也有显著性增高（P〈0．05）。结论 糖尿病鼠脑微血管内皮P-选择素表达上凋与慢性低度炎症反应有关，可能是糖尿病大鼠脑微血管内皮功能紊乱的机制之一。

Objective To explore the mechanisms of cerebral mierovaseular disorders in rats with diabetes. Methods Diabetes was induced by injecting 1%, streptozoein （STZ）. Twenty-four Sprague-Dawley rats were randomly assigned into three groups： eontrol group normal rats, DM8 group with an 8-weeks course of diabetes and DM24 group with 24-weeks course of diabetes （ n = 8 each）. The expression of P-selectin （Ps） in cerebral microvascular and plasm C-reactive protein （CRP） were detected. Results Ps was not expressed in the control group. Ps positive endothelial cells were mostly expressed in microvessels with a diameter of 7.5-30μm in rats with diabetes. The expression of Ps was significant of higher in the two DM groups than that in the eontrol group （ P 〈0.01 ）. There were significant differences in the Ps expression between the DM24 and DM8 groups （P 〈0.05 ）. Plasm CRP concentration increased in the DM8 and DM24 groups compared with that in the control group （ P 〈 0.01 ）. A significant difference was also observed in the CRP concentration between the DM8 and DM24 groups （ P 〈 0. 005 ）. Conclusions The increased expression of Ps in cerebral microvascular may be related to chronic low grade inflamemation, which may be one of the mechanisms of cerebral mieroxascular disorders in diabetes rats.