【摘要】 在与上一篇论文（关于A₁区）相同的条件下,（1） 用谷氨酸钠兴奋大鼠A₅区,和A₁区类似,也产生明显的降压、降心率效应。（2） 切断双侧颈迷走神经也明显衰减兴奋A₅区的心血管作用。（3） 将不同受体阻断剂注入延髓头端腹外侧区对兴奋A₅区引起的降压,降心率反应之影响,与A₁区比较有所不同:酚妥拉明、心得安、纳洛酮和荷包牡丹碱均能明显衰减A₅区的降压、降心率效应（心得安和荷包牡丹碱甚至反转之）,表明除α-,β-,GABA受体之外,阿片受体也中介A₅区的降压降心率作用。更多还原

【Abstract】 Experiments were performed under the same condition described in the accompanying paper. （1） Injection of sodium L-glutamate （Glu） into A₅ area of rat induced depressor and bradycardia responses, as Glu-injection into A₁ aera did. （2） Bilateral vagotomy also markedly attenuated the cardiovascular effect of Glu-injection into A₅. （3） Influences of the receptor blockers injected into rostral ventrolateral medulla （RVL） on the depressor and bradycardia responses of Glu-injection into A₅ were slightly different from those of the same receptor blockers administered into RVL: phentolamine,propranolol, naloxone and bicuculline all markedly reduced the depressor and bradycardia effects of As-excitation （propranolol and bicuculline even reversed these effects）. These results indicate that not only α-β-, GABA receptors, but also opiate receptors mediate the depressor and bradycardia effects of A₅.更多还原