实验性高胆固醇血症兔离体主动脉功能变化的研究

Hypercholesterolemia Effects on Vasomotion of Isolated Aorta Ring in Rabbits

目的 :探讨高胆固醇血症对血管功能的影响。方法 :2 0只新西兰雄性兔随机分为 2组 :正常饮食组 (nor-mal cholesterol,NC) 10只及高胆固醇饮食组 (hypercholesterol,HC) 10只。 4周后取出每只兔的降主动脉 ,5 mm宽动脉环放置于含有 2 5 ml Kreb液的组织 -器官水浴系统中。分别测量游离血管对乙酰胆碱 (10 - 1 0～ 10 - 5 m ol/L)的舒张反应及对去甲肾上腺素 (10 - 1 0～ 10 - 5 m ol/ L)的收缩反应。结果 :2组兔血胆固醇有显著差异 ,其中 NC组(30 .1± 11.2 ) mg/ dl,HC组 (987.3± 110 .0 ) mg/ dl(P <0 .0 1) ;HC组血管对乙酰胆碱舒张反应与 NC组比较明显减弱 ,HC组最大为 (5 8.5 0± 6 .17) % ,NC组最大为 (10 3.2± 6 .9) % (P <0 .0 1) ;HC组血管对去甲肾上腺素反应增强 ,最大收缩力 HC组为 (4 .15± 0 .5 6 ) g,NC组为 (2 .9± 0 .3) g(P <0 .0 5 )。 2组动脉病理学检查无动脉硬化的改变。结论 :高胆固醇血症降低血管内皮依赖性舒张反应 ,增加血管对去甲肾上腺素的收缩反应。高胆固醇血症时血管内皮功能改变早于动脉粥样硬化的结构改变。

Objective:Our aim was to determine of hyperchosterolemia effects the vasomotion of rabbits′ aorta ring. Methods:Twenty New Zealand male rabbits were randomly divided into two groups(10 rabbits each): normal cholesterol(NC) and 0.5% hypercholesterol(HC). Four weeks later, descending aorta was excised from each animal. Aortic rings, 5 mm wide, were placed vertically between 2 hooks in tissue organ bath system containing 25 ml Kreb solution. Vasodilating response to acetylcholine(10 -10 to 10 -5 mol/L) and constricting response to norepinephrine(10 -10 to 10 -5 mol/L) were measured in isolated aortic rings. Paired studies were conducted in the hyperchosterolemia and control rabbits. Results:There was a significant difference in total serum cholesterol levels between NC and HC(30.1±11.2 mg/dl and 987.3±110.0 mg/dl(P<0.01). Vessels exhibited a decreased vasodilating response to acetylcholine in HC group(maximal 58.50±6.17% in HC and 103.2±5.9% in NC,P< 0.01 ) and an increased constrictor response to norepiphrine in HC group(maximal developing force 4.15±0.56 g in HC and 2.9 ±0.3 g in NC,P<0.05). No aortic atherosclerosis was found by morphogical studies.Conclusion:Hypercholesterolemia decreases endothelium dependent vasorelaxation. Vascular endothelial dysfunction develops earlier than atherogenesis in this rabbit model.