脑缺血再灌注后激肽释放酶-激肽系统的动态变化

Altered Expression of the Kallikrein-Kinin System in the Ischemia/reperfusion Rat

目的:观察实验性脑缺血再灌注损伤后不同时期组织型激肽释放酶活性、缓激肽含量、缓激肽B1、B2受体的动态表达情况,并探讨其在脑缺血病理生理过程中的作用。方法:在大鼠大脑中动脉梗死模型中,通过生物酶学方法及ELISA技术测定缺血前和再灌注后不同时间缺血组织内激肽释放酶活性及缓激肽含量。RT-PCR及Westernblot测定缓激肽B1、B2受体的基因及蛋白表达水平。结果:实验性脑缺血可诱导脑组织内激肽释放酶-激肽系统(KKS)各组分表达增高,而且缓激肽两种受体在脑缺血后各时间点动态表达趋势不同。结论:KKS在脑缺血后的病理生理过程中发挥了重要作用。两种受体表达时相差异揭示了B1、B2两种受体在缺血后各时期的作用可能不同。

Aim： To observe the concentration of bradykinin, the expression of B1 and B2 bradykinin receptors at different time points after cerebral ischemia and reperfusion. Methods： Transient middle cerebral artery occlusion （MCAO） modal was made following the intraluminal thread technique. The enzyme activity of tissue kallikrein and the concentration of bradykinin in the ischemic brain tissue were tested before ischemia and at the different time after reperfusion. RT-PCR and Western blot were employed to detect the expression of mRNA and protein of bradykinin receptors before ischemic damage and at the 3^th, 6^th ,12^th ,24^th ,48^th, 72^th hour and the 4^th, 7^th day after reperfusion. Results： Ischemic damage to the brain results in the increase of several components of the KKS system.The expression of B 1 and B2 receptor at different time points after reperfusion has different tendency. Conclusion： This system may play an important role in the pathophysiologic process after cerebral ischemia. While the phasic difference between the expression of B 1 and B2 receptor indicates that they may play different roles after cerebral ischemia.