映山红花总黄酮阻断Rho激酶促进大鼠冠状动脉舒张作用的机制

Mechanism of total flavonoids of Rhododendron blocking Rho kinase-induced vasodilation of coronary artery in rats

目的:探讨映山红花总黄酮(total flavones of rhododendra,TFR)阻断Rho激酶促进大鼠冠状动脉舒张作用的机制。方法:用siRNA技术分别制备ROCK1-siRNA和ROCK2-siRNA大鼠,Western-blot测定冠状动脉组织中ROCK1和ROCK2,用微血管张力法测定冠状动脉血管张力,用Y27632和TFR检测正常血管和干扰后血管的舒张功能。结果:与Control组比较,ROCK1-siRNA组中ROCK1和ROCK2-siRNA组中ROCK2表达明显降低,而Negative siRNA和Transfection reagent组中ROCK1和ROCK2表达无明显差异,即siRNA干扰技术能有效降低冠状动脉组织中ROCK1和ROCK2表达;与溶媒组比较,TFR和Y27632能引起干扰后的血管产生舒张作用,而与正常组比较,TFR和Y27632显著减弱干扰后的血管的舒张作用;TFR对ROCK2-siRNA转染的冠状动脉舒张作用的Emax高于ROCK1-siRNA转染的血管的Emax。结论:TFR对大鼠冠状动脉的舒张作用与阻断ROCK有关,并且可能选择性作用于ROCK1。

AIM:To investigate the mechanism of total flavonoids of Rhododendron blocking Rho kinase-induced vasodilation of coronary artery in rats.METHODS:ROCK1-siRNA and ROCK2-siRNA rats were prepared by siRNA technique.ROCK1 and ROCK2 of coronary artery were measured by western-blot.Coronary artery tension was measured by a microvascular tension system.The diastolic function of normal and interfered vascular was detected with Y27632 and TFR.RESULTS:Compared with control group,the expression of ROCK1in ROCK1-siRNA group and expression of ROCK2 in ROCK2-siRNA group were decreased,while the expression of ROCK1 and ROCK2 in negative siRNA and transfection reagent groups were not significant difference,siRNA interference technology can effectively reduce expression of ROCK1 and ROCK2 of coronary artery tissue.Compared with vehicle group,TFR and Y27632 can cause vasodilation in ROCK1-siRNA and ROCK2-siRNA transfected vascular.Compared with normal group,TFR and Y27632 significantly attenuated the vasodilation in ROCK1-siRNA and ROCK2-siRNA transfected vascular;The Emax of vasodilation which induced by TFR in ROCK2-siRNA group was higher than ROCK1-siRNA group.CONCLUSION:The vasodilation of coronary artery which induced by total flavonoids of Rhododendron on rats is associated with blocking ROCK and may selectively act on ROCK1.