电刺激颈迷走神经中枢端引起两相加压反应的不同中枢机理——Ⅰ.迷走加压反应

MECHANISMS UNDERLYING DIPHASIC PRESSOR RESPONSE TO STIMULATION OF CERVICAL VAGAL AFFERENTS——Ⅰ. THE VAGUS-PRESSOR RESPONSE

乌拉坦麻醉、双侧切断颈迷走神经的大鼠,电刺激颈迷走神经中枢端可引起“迷走加压反应”。分别向双侧蓝斑(LC)内注入普鲁卡因或向双侧延髓头端腹外侧区(RVL)内注入阿托品,间脑-中脑之间横断脑干或双侧室旁核(NPV)内注射普鲁卡因均可明显衰减该反应。心得安(i.v.)也能衰减之,但酚妥拉明(i.v.)则否。以上实验结合以往结果提示:迷走加压反应系通过LC-NPV(主)和LC-RVL加压系统实现。

In urethane-anesthetized and bilateral vagotomized rats, stimulation of the central end of the cer-vical vagus evoked a diphasic pressor response, including an initial short-term pressor response and aslow long-lasting "vagus-pressor response". Injection of procaine into bilateral locus coeruleus (LC) oratropine into rostral ventrolateral medulla (RVL), transection of brain between diencephalon and me-sencephalon or injection of procaine into bilateral nucleus paraventricularis (NPV) all markedly atte-nuated the vagus-pressor response. Intravenous injection of propranolol also reduced this hypertensiveresponse, but phentolamine (i.v.) did not. Taken together with the findings of our other works oncentral mechanisms of LC-pressor effect, the above results suggest that vagus-pressor response is medi-ated by LC-NPV (mainly) and LC-RVL pressor systems.