球囊损伤血管内皮后血管紧张素ⅡAT_1受体mRNA的变化

Expression of angiotensin Ⅱ AT_1 receptors mRNA after vascular balloon injury in rats

目的 研究球囊损伤血管内皮后内膜增生的过程及血管紧张素ⅡAT1受体mRNA的变化。方法 建立球囊剥脱大鼠主动脉内皮模型 ,将大鼠随机分为对照组 (n =2 4)和手术组 (n =2 4) ,各组分别在内皮损伤后 3、7、14和 2 8d取主动脉组织 ,通过组织学方法及逆转录聚合酶链反应 (RT -PCR)技术检测主动脉内膜增生的过程及AT1受体mRNA的水平。结果 (1)AT1受体mRNA于术后 3d已明显增加 ,并于术后 14d达高峰 ,术后 2 8d恢复至对照组水平。 (2 )内皮损伤后 3d已有增殖的血管平滑肌细胞 (VSMC)移行至内膜层 ;损伤后 7d内膜开始增生 ;损伤后 14dVSMC的增殖及内膜的增生更加明显 ;损伤后2 8dVSMC的增殖明显减弱 ,但细胞外基质成份增加 ,内膜继续增生。结论 血管内皮损伤后内膜增生的过程中AT1受体mR NA表达增加。

Objective To investigate the process of intimal thickening and the expression of angiotensinⅡAT 1 receptors mRNA after vascular balloon injury in rats.Methods To make models of rats of aortic endothelial denudation by a balloon catheter,the rats were randomly allocated into two groups.Group 1(n=24)served as controls.Group 2(n=24)were given aortic vascular balloon injury.The process of intimal thichening and the level of AT 1 receptors mRNA were detected at day 3,7,14 and 28 after balloon injury by histological method and reverse ranscription polymerse chain reaction (RT-PCR)technique,respectively.There are six rats in each time point.Results (1)The expression of AT 1 receptros mRNA incresaed significantly at day 3 after balloon injury and reached its peak at day 14,but restored to the level of controls at day 28.(2) The migration and proliferation of vascular smooth muscle cells(VSMC)had existed at day 3 after balloon injury. The intimal thickening had begun at day 7 after injury,and they are more significant at day 14.The proliferation of VSMC decreased obviously at day 28,but extracellular matrix in creased and intimal thickening continued.Conclusion The expression of AT 1 receptors mRNA increases in the process of intimal thickening after vascular balloon injury.