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

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.