【摘要】 电刺激大鼠中缝隐核(RO)引起的减压反应,可被双侧延髓头端腹外侧区(RVL)内预先注射赛庚啶或荷包牡丹碱、静脉注射酚妥拉明或甲基阿托品衰减,但心得安(i,v.)无明显效应。结果提示,该反应可能部分通过RO的5-HT能投射纤维作用于RVL内的GABA能中间神经元,抑制RVL-交感兴奋神经元,使交感缩血管神经活动减弱而实现。心迷走中枢兴奋也参与此反应。更多还原

【Abstract】 In urethane anesthetized rats, electrical stimulation of the nucleus raphe obscurus (RO) elicited afall in blood pressure. The depressor response could be reduced by preinjection of cyproheptadine (a5HT-antagonist) or bicuculline (a GABA-receptor blocker) into bilateral rostral ventrolateral medulla(RVL); and could also be markedly attenuated by phentolamine or methyl atropine (i.v.), but not bypropranolol (i.v.). The results suggest that RO exerts the depressor response via its 5HT-projectionsacting upon the GABAergic interneurons in RVL, the latter inhibited the RVL-sympathoexcitatoryneurons, causing a decrease in activity of the sympathetic vasoconstrictor nerve; in addition, excitationof the cardiac vagal center is also involved in the depressor response.更多还原