侧脑室注射一叶萩碱的心血管效应及作用机制

Cardiovascular effects of lateral intracerebroventricular injection of L-securinine

在麻醉大鼠侧脑室注射左旋一叶萩碱 (L Sec) ,记录动脉血压 (AP)、心率 (HR)及肾交感神经放电(RSND) ,观察前脑室周系统GABA能紧张性活动改变引起的心血管效应。结果如下 :(1)L Sec可引起RSND增加、AP升高和HR加快 ,并呈一定剂量 效应关系 ;但L Sec作用明显弱于bicuculline (Bic)。 (2 )L Sec既能拮抗musci mol(Mus) ,又能拮抗baclofen (Bac)引起的交感抑制和降压反应。上述结果提示 :(1)前脑室周部位存在GABA能抑制机制 ,对交感心血管系统具有紧张性抑制作用 ,L Sec解除了这种抑制 ,使交感神经系统传出活动增强 ,因而产生升压作用。 (2 )L Sec可能是一种非选择性的GABA受体拮抗剂。

To investigate cardiovascular effects of changed GABA ergic tonic activation in periventricular forebrain, arterial pressure (AP), heart rate (HR) and renal sympathetic nerve discharge (RSND) were recorded in anesthetized rats when L securinine (L Sec) was administered into the lateral intra^ce^re^bro^ventricle. L Sec elicited dose dependent increases in RSND, AP and HR, which were much weaker than those of bicuculline. L Sec antagonized the sympatho inhibitory and depressor effects evoked by both muscimol and baclofen. These results indicate that GABA ergic inhibition originating from periventricular forebrain may suppress tonically sympathetic outflow to cardiovascular system which is disinhibited by L Sec, and L Sec is likely an unselective GABA receptor antagonist. [WT5HZ]