一氧化氮及去内皮对颈动脉窦压力感受器活动的影响

本实验应用自制的颈动脉窦窦内劝灌流－窥上表面灌流的双重灌流装置,研究了外源性一氧化氮及内皮对家名义离体ＣＳ压力感受器活动的影响,并进一步探讨其作用机制。

Effects of no and endothelium on carotid baroreceptor activity

The present study was undertaken to examine the effects of endothelium and exogenous NO on the baroreceptor discharge of the carotid sinus. The baroreceptor activity (BRA) was recorded from the rabbit carotid sinus-sinus nerve (CS-CSN) preparation using a chamber for superfusing and perfusing the tissue. The results are as follows. (1)The CSN hasal discharge could be divided into two components, a low-amplitude component and a high-amplitude one. The high-amplitude discharge was dependent on pulsatory perfusing pressure, but did not respond to classical chemoreceptor stimulants,indicating its baroreceptive origin. (2) The BRA was decreased after removal of the endothelium. (3 ) L-arginine (L-arg), as exogenous NO, initiated BRA in a dosedependent manner, which was prevented by precedent inhibition of NO synthase or by removalof the endothelium. (4) Inhibition of guanine nucleotide cyclase with methylene blue effected neither the hasal BRA nor the response of BRA to L-arg. These results indicate that stimulation of BRA by exogenous NO may be mediated by the endothelium,but cGMP dose not seem to be involved.