Cartier R, Bouchard D, Buluran J
Service de Chirurgie Cardiovasculaire, Institut de Cardiologie de Montréal, Québec, Canada.
Ann Chir. 1996;50(8):673-81.
Fibromuscular intimal injury is frequent after coronary or peripheral angioplasty. Peroxidation of circulating and membrane lipids have been implicated in intimal hyperplasia and endothelial dysfunction following direct arterial trauma. The aim of this study was to evaluate the effects of natural membrane antioxidant, vitamin E (VE), on the vascular reactivity of the regenerated endothelium. A first group of rats (n = 10) was pretreated with VE 100 IU/kg/day for a week before undergoing aortic (thoracic) endothelial denudation with a Fogarty catheter. Rats were then fed with the same VE supplemented diet for a 2-month period. A second group (n = 10), was similarly denudated and fed with soya oil (SO), VE vehicle, for the same period. A third group (n = 10) was denuded and used as control (CL). Endothelial-dependent and independent relaxations were assessed in organ chambers with acetylcholine (ACH), adenosine diphosphate (ADP), histamine (HIS), 5-hydroxytryptamine (5-HT) and sodium nitroprusside (SNP). Endothelial regeneration was evaluated with Evans blue staining. Vascular relaxation to SNP was not affected either by the regeneration process or the VE supplementation. However, endothelial-dependent relaxation to ACH and HIS were significantly impeded in the regenerated endothelium compared to control but was not influenced by the VE or the SO supplementation. Vascular contraction to 5-HT was significantly decreased in VE group compared to the other groups. Morphometric studies with Evans blue staining showed over 95% regeneration of the endothelial surface of the denuded aortas. Our results suggest that in spite of a complete anatomical regeneration, endothelial cells did not resume predenudation function. Endothelial-independent relaxation was preserved in all groups indicating that smooth muscle function was not altered by the regenerating process. The presence of dietary supplement of VE (up to 20 fold the daily requirement) did not prevent the endothelial dysfunction to ACH and HIS but attenuated the vaso-contraction to 5-HT and then could contribute to decreased vascular tone in endothelium-regenerated vessels.
冠状动脉或外周血管成形术后常发生纤维肌性内膜损伤。循环脂质和膜脂质的过氧化作用与直接动脉损伤后的内膜增生和内皮功能障碍有关。本研究的目的是评估天然膜抗氧化剂维生素E（VE）对再生内皮血管反应性的影响。第一组大鼠（n = 10）在使用Fogarty导管进行主动脉（胸段）内皮剥脱术前一周，每天用100 IU/kg的VE预处理一周。然后，大鼠在两个月的时间里喂食相同的补充VE的饮食。第二组（n = 10）同样进行内皮剥脱，并在同一时期喂食大豆油（SO），即VE的赋形剂。第三组（n = 10）进行内皮剥脱并用作对照（CL）。在器官浴槽中用乙酰胆碱（ACH）、二磷酸腺苷（ADP）、组胺（HIS）、5-羟色胺（5-HT）和硝普钠（SNP）评估内皮依赖性和非依赖性舒张。用伊文思蓝染色评估内皮再生。血管对SNP的舒张不受再生过程或VE补充的影响。然而，与对照组相比，再生内皮对ACH和HIS的内皮依赖性舒张明显受到阻碍，但不受VE或SO补充的影响。与其他组相比，VE组对5-HT的血管收缩明显降低。伊文思蓝染色的形态计量学研究显示，剥脱主动脉的内皮表面再生超过95%。我们的结果表明，尽管有完整的解剖学再生，但内皮细胞并未恢复剥脱前的功能。所有组的内皮非依赖性舒张均得以保留，表明平滑肌功能未因再生过程而改变。饮食中补充VE（高达每日需求量的20倍）并不能预防对ACH和HIS的内皮功能障碍，但可减轻对5-HT的血管收缩，进而可能有助于降低内皮再生血管的血管张力。
