【摘要】 于兔延髓中线区闩部头端处微量注射5-HT 受体阻断剂肉桂硫胺(4μg溶于2μl中)可减弱躯体传入冲动对刺激下丘脑诱发的室性期前收缩(HVE)的抑制效应;微量注入阿片受体阻断剂纳洛酮(4μg溶于2μl中)则可完全消除此抑制效应。损毁延髓中线区后,中脑中央灰质微量注入5-HT 或吗啡均不再能抑制 HVE。上述现象提示,躯体传人冲动抑制 HVE 的效应依赖于延髓中线区内啡肽和5-HT 的活动,中脑中央灰质内5-HT 和内啡肽对 HVE 的抑制作用也可能主要是通过延髓中线区的活动而实现。文中还就躯体传入冲动抑制 HVE 的中枢机制进行了讨论。更多还原

【Abstract】 Microinjection of cinanserine(4μg in 2μl)into the medial mudulla attenuatedthe inhibitory effect of somatic afferent nerve stimulation on the hypothalamicstimulation-induced ventricular extrasystoles(HVEs),while microinjection ofnaloxone(4μg in 2μl)into the same area completely blocked the inhibitory effect.The number of HVEs was reduced following microinjection of either 5-HT ormorphine into the central gray matter.This effect of 5-HT or morphine microinjec-tion was abolished after destroying the medial portion of the medulla.These results suggest that the inhibitory effect of somatic afferent nervestimulation on HVEs is mediated by activation of opiate and serotonin receptors inthe medial medulla.The neural mechanism of the inhibitory effect of somaticafferent stimulation on HVEs is discussed.更多还原