茶多酚对动脉粥样硬化大鼠血管内皮的保护作用

目的通过复制大鼠动脉粥样硬化(Arteriosclerosis,AS)模型,观察茶多酚对AS大鼠血管内皮功能的影响.方法将40只Wistar大鼠随机分为正常组(NC组)、模型组(AS组)、茶多酚低剂量组(TPL组,0.2 g/κg)、茶多酚高剂量组(TPH组,0.4 g/κg),9周后测定血管内皮依赖性舒张功能.结果 1)血管内皮依赖性舒张功能:AS组与NC相比,大鼠胸主动脉血管环在10-9~10-4mol/L浓度的Ach溶液中血管内皮舒张率明显降低(P0.01);TPL,TPH与AS组相比,大鼠胸主动脉血管环在10-9~10-4mol/L浓度的Ach溶液中内皮舒张率明显升高(P0.05);2)血管内膜/中膜厚度比:AS组与NC相比,内膜/中膜厚度比明显增大(P0.01),具有统计学意义;TPL,TPH与AS组比较,内膜/中膜厚度比明显降低(P0.01);3)主动脉形态学观察:AS组大鼠动脉壁可见多处隆起于内膜表面的典型粥样斑块;动脉内皮细胞脱落,内膜增厚、断裂;中膜平滑肌明显萎缩,排列不规整.NC组无形态学改变,其他各组改变较轻,未见粥样斑块形成.结论茶多酚具有保护血管内皮细胞的功能.

Protective Effect of Tea Polyphenols on Vascular Endothelium in Rats with Atherosclerosis

Objective To observe the effect of tea polyphenols on endothelial function in arteriosclerosis rats (AS) model. Method A total of 40 Wistar rats were randomly divided into normal group(NC group),model group(AS group),tea polyphenols low dose group(TPL group,0. 2 g/kg),tea polyphenols high dose group(TPH group,0. 4 g/kg),and determination after 9 weeks,the vascular endothelial dependent diastolic function was determined. Results (1) Endothelium dependent diastolic function:In 10-9 ~ 10-4 mol / L Ach solution,the vascular endothelial relaxation rate of thoracic aorta ring in AS group significantly decreased compared with NC group,(P<0. 01),and the relaxation rate of TPL and TPH group showed obvious increases compared with AS group(P<0. 05). (2) Vascular intima/media thickness ratio: The intima/media thickness ratio of AS group significantly increased compared with NC group ( P<0. 01 ), and the ration of TPL and TPH group were significantly lower than AS group(P<0. 01). (3) Observations on aortic morphology: In AS group,the rat's arterial wall showed many typical arteriosclerosis plaques bulging from the surface of intima with evfoliation of arterial endothelial cells, thickening and breaking of intima. Smooth muscle of tunica media showed marked atrophy with irregular arrangement. There was no morphological change in NC group, and were milder changes with no arteriosclerosis plagues formation in other groups. Conclusion Tea polyphenols could protect vascular endothelial cells.