摘要
目的 研究球囊致血管损伤后血管内膜增生的过程、血管紧张素ⅡAT 1受体mRNA的变化及血管紧张素Ⅱ受体拮抗剂 (氯沙坦 )对它们的影响。方法 球囊剥脱大鼠主动脉内皮 ,并随机分为对照组 (n =2 4)、手术组 (n =2 4)和氯沙坦治疗组 (n =2 4)。分别在术后 3、 7、 14和 2 8d ,取主动脉 ,通过组织学检查和逆转录聚合酶链反应 (RT PCR)技术检测内膜增生的情况、血管紧张素ⅡAT 1受体mRNA的水平及非肽类血管紧张素Ⅱ受体拮抗剂氯沙坦 (30mg/kg/d)对它们的影响。结果 ①AT 1受体mRNA于术后 3d已明显增高 ,并持续至术后 14d。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 ;伤后 14dVSMC的增殖及内膜增生更为明显 ;术后 2 8dVSMC的增殖明显减弱 ,细胞外基质增加 ,内膜继续增生。③使用氯沙坦后AT 1受体mRNA的表达增加 ,但VSMC的移行、增殖减弱 ,内膜增生程度减轻。结论 血管损伤后内膜增生的过程中AT 1受体mRNA的表达增加 ,氯沙坦增加AT 1受体mRNA的表达 。
Objective To investigate the process of neointimal formation,the expression of angiotensin Ⅱ AT 1 receptor mRNA and the effect of Losartan,an antagonist of AT 1 receptor after vascular balloon injury in rats.Methods Rat models of aortic endothelial denudation was made by balloon catheter.Rats were randomly allocated into three groups:Group 1(n=24) served as controls.Group 2 (n=24)received vascular balloon injury.Group 3(n=24)were given Losartan(30mg/kg/d) from 1 day befor injury to 28 days after vascular injury.The level of AT 1 receptors mRNA and the process of intimal thickening were investigated at day 3,7,14 and 28 after injury by histological method and RT PCR technique,respectively.Results ①The expression of AT 1 receptor mRNA increased significantly at day 3 after injury and remained high at day 14.②The migration and proliferation of vascular smooth muscle cells(VSMC)were already prsesent at day 3 after balloon injury.The thickening of intima had began at day 7 after injury,and become more significant at day 14.The proliferation of VSMC decreased obviously at day 28,but extracellular matrix increased and the intimal thickening continued.③When given Losartan,the level of AT 1R mRNA increased,but the intimal thickening was reduced.Conclusion The expression of AT 1R mRNA increases in the process of intimal thickening after balloon injury.Losartan upregulates the expression of AT 1R mRNA,but can prevent intima from thickening.
出处
《中华急诊医学杂志》
CAS
CSCD
2002年第1期33-36,共4页
Chinese Journal of Emergency Medicine
