颈动脉内注入腺苷对呼吸,血压和肾交感神经活动的影响

在33只麻醉家兔,观察了颈动脉内注入腺苷所诱发的平均动脉压、心率,呼吸和肾交感神经活动的变化。结果如下:(1)颈动脉内注入腺苷后,平均动脉压呈剂量依赖性下降;呼吸加快,深度变化不明显,剪断窦神经后注入腺苷,仍引起平均动脉压下降,而呼吸变化消失。(2)隔离的颈动脉窦灌流液内加入腺苷后,平均动脉压下降,心率减慢;颈动脉体(CB)失活后反应消失。(3)将腺苷灌注到颈动脉窦区后,平均动脉压下降,肾交感神经传出放电活动增加,CB 失活或剪断窦神经后,反应消失。由此提示:腺苷可作为兴奋 CB 的一种物质,引起平均动脉压降低,心率减慢,呼吸加强和肾交感神经放电活动增加。

EFFECTS OF INTRACAROTID INJECTION OF ADENOSINE ON RESPIRATION BLOOD PRESSURE AND RENAL SYMPATHETIC NERVE ACTIVITY

Changes of mean arterial pressure(MAP),heart rate(HR),respiration andrenal sympathetic nerve activity(RSNA)induced by close-arterial administra-tion of adenosine to carotid body(CB)were observed in 33 anesthetized rabbits.The results were as follows:(1)In response to intracarotid injections of adenosine,MAP decreased in a dose-dependent manner,while the frequency of respirationincreases with little change in depth.Following carotid sinus denervation,intracaro-tid injection of adenosine still resulted in a decrease of MAP but with no changesin respiration.(2)By adding adenosine to perfusate of the isolated carotid sinus,both MAP and HR decreased,but these effects could be abolished by inactiva-tion of carotid body.(3)MAP decreased and RSNA enhanced during perfusingadenosine into carotid sinus.These effects could be abolished by the section ofsinus nerve or inactivation of CB.From the results obtained,it is considered thatadenosine is capable of activating CB,decreasing MAP and heart rate but with aconcomitant increases in respiration and RSNA.