血管紧张素Ⅱ对家兔离体血管条去甲肾上腺素收缩作用的增敏效应

THE SENSITIZATION EFFECT OF ANGIOTENSIN Ⅱ ON RABBIT AORTA STRIPS TO NOREPINEPHRINE

本实验证实去甲肾上腺素(NE)和血管紧张素Ⅱ(AⅡ)对家兔离体胸主动脉条均具有收缩作用。且二者具有协同作用,并证明AⅡ可以增敏NE的收缩作用。应用AⅡ阻断剂[Sar′,Ala^5]—AⅡ可阻断AⅡ对离体胸主动脉条的收缩作用,但不能阻断NE的效应。说明AⅡ、NE不是作用于同一受体上。

It was demonstrated that both norepinephrine (NE) and angiotensin Ⅱ (A Ⅱ) exert a contraction action on aorta strips in rabbits in vitro. Furthermore, A Ⅱ could not only increase synergically this action of NE, but also sensitize the aorta strips to NE. [Sar', Ala3]-angiotensin Ⅱ, an antagonist of angiotensin Ⅱ, could block the contraction effect of A Ⅱ on aorta strips of rabbits , but not the effect of NE. It is suggested that A Ⅱ and NE do not act on the same receptors.