四氢生物喋呤修复高胆固醇血症兔血管内皮功能

Tetrahydrobiopter in Restores Endothelial Function in Rabbits With Hyperchole terolaemia

目的 :研究四氢生物喋呤 (BH4)对高胆固醇喂养兔的血管内皮功能的影响。 方法 :2 4只新西兰兔随机分 4组每组 6只。正常饮食组、高胆固醇饮食组、叶酸加高胆固醇饮食组、BH4加高胆固醇饮食组。喂养 5周后 ,测定血中总胆固醇及一氧化氮 (NO)水平 ,并取胸主动脉 ,进行离体血管环实验 ,测定血管条对乙酰胆碱的累积浓度舒张反应。 结果 :①血脂及NO水平变化 :与正常饮食组比较各胆固醇喂养组血清总胆固醇明显增高 ,有极显著性差异 (P <0 0 1)。同时测定NO显示 ,高胆固醇饮食组较正常饮食组NO水平明显减低 ,有极显著性差异 (P <0 0 1) ;叶酸加高胆固醇饮食组、BH4加高胆固醇饮食组与高胆固醇饮食组比较NO水平也明显减低 ,有显著性差异。②动脉对乙酰胆碱的最大舒张功能 :不同组别的动脉对不同浓度的乙酰胆碱最大舒张功能是不同的 ,高胆固醇饮食组的舒张功能较其他 3组明显下降 ,叶酸加高胆固醇饮食组和BH4加高胆固醇饮食组的舒张功能均有不同程度的恢复。 结论 :高胆固醇血症导致内皮功能紊乱 ,BH4和其类似物叶酸对高胆固醇血症兔的血管内皮功能紊乱有保护作用。

Objective:To e amine the e ect o tetrahydrobiopterin,an e ential co actor or nitric o ide yntha e,on endothelial dy unction in hyperchole terolemic rabbit . Method :Twenty our rabbit were randomi ed to receive normal diet(group A, n =6),chole terol diet(group B, n =6),chole terol diet plu olic acid(group C, n =6)chole terol diet plu tetrahydropterin(group D, n =6) or 5 week .A ter pla ma total chole terol (TC) ,triglyceride (TG) and NO concentration were measured,thoracic aortas were removed and cut into ring segments about 3 mm long,then the endothelium dependent maximal relaxiation to Ach by accumulated concentration were obtained. Results:Compared with the control group,TC concentration in B,C or D were markedly increased ( p <0 05) .There was no diffence among group B,C or D.Compared with group A,NO concentration in group B was markedly decreased (45 42±10 56 μmol/ L vs 122 95±13 03 μmol/L, p Z <0 01) .Compared with group B,NO concentration in C or D group was markedly increased.Compared with group A,the maximal relaxations of arterioles induced by Ach were markedly decreased in group B.Compared with group B,the maximal relaxations of arterioles induced by Ach were markedly increased in group C or D. Conclusion:Hypercholesterolemia results in the endothelial dysfunction.Tetrahydrobiopterin and folic acid can restore endothelial function in rabbits with hypercholesterolemia.