Allen A M, McKinley M J, Oldfield B J, Dampney R A, Mendelsohn F A
Department of Medicine, University of Melbourne, Austin Hospital, Heidelberg, Victoria, Australia.
Clin Exp Hypertens A. 1988;10 Suppl 1:63-78. doi: 10.3109/10641968809075964.
Angiotensin II (Ang II) acts centrally to modulate autonomic activity and cardiovascular function. Using in vitro autoradiography we have determined the distribution of putative receptors for ANG II in brain regions associated with the baroreflex pathway. Ang II receptor binding sites were observed in the nucleus of the solitary tract (NTS), the dorsal motor nucleus of vagus, the rostral and caudal ventrolateral medulla and intermediolateral cell column of the spinal cord. Receptor binding sites were also observed in the nodose ganglion and in association with nerve fibres in the heart. Nodose ganglionectomy and vagal ligation studies revealed that Ang II receptor binding sites are produced in the nodose ganglion and transported in the vagus nerve to terminals of vagal afferent neurones. In the NTS these presynaptic receptors could mediate the known baroreflex inhibitory action of Ang II by inhibition of neurotransmitter release. In the cat, Ang II receptors were sharply localized in the rostral ventrolateral medulla to the subretrofacial nucleus. Microinjection of Ang II (10-50 pmoles) into this region induced a sympathetically-mediated pressor response. Together these results demonstrate several regions within the baroreflex arc which contain Ang II receptors, at which Ang II may modulate cardiovascular control and autonomic function.
血管紧张素II（Ang II）在中枢发挥作用，调节自主神经活动和心血管功能。我们利用体外放射自显影技术，确定了与压力反射通路相关的脑区中假定的Ang II受体的分布。在孤束核（NTS）、迷走神经背运动核、延髓头端和尾端腹外侧以及脊髓中间外侧细胞柱中观察到了Ang II受体结合位点。在结状神经节以及与心脏中的神经纤维相关的部位也观察到了受体结合位点。结状神经节切除术和迷走神经结扎研究表明，Ang II受体结合位点在结状神经节中产生，并通过迷走神经运输到迷走神经传入神经元的终末。在NTS中，这些突触前受体可通过抑制神经递质释放来介导Ang II已知的压力反射抑制作用。在猫中，Ang II受体在延髓头端腹外侧精确定位于面后核以下区域。向该区域微量注射Ang II（10 - 50皮摩尔）可诱发交感神经介导的升压反应。这些结果共同表明，压力反射弧内有几个区域含有Ang II受体，Ang II可能在这些区域调节心血管控制和自主神经功能。
