Wennergren G, Oberg B
Pflugers Arch. 1980 Sep;387(2):189-95. doi: 10.1007/BF00584271.
Cardiovascular adjustments induced by topical application of drugs on a restricted area on the ventral surface of the medulla oblongata, corresponding to the caudal part of the rostral chemoreceptor area and the intermediate area, have been studied in chloralose-anesthetized cats. Topical application of GABA or glycine on these structures resulted in blood pressure fall, bradycardia, vasodilatation in the kidney and the skeletal muscles and also depression of respiration. Similar responses except for a slight tachycardia occurred with application of physostigmine. Application of GABA resulted in a marked attenuation of the reflex vasoconstrictor responses to removal of arterial baroreceptor restraint (carotid occlusion), particularly in the kidney, and to disappearance of the reflex renal vasodilatation to baroreceptor stimulation. The findings suggest that GABA application leads to a general diminution of the tonic vasomotor neuron activity, and with regard to renal vasomotor neurons a virtual cessation. Atropine methylnitrate application induced blood pressure rise, increased peripheral resistance in both skeletal muscle and kidney and a strongly potentiated renal vasoconstrictor response to carotid occlusion. The results indicate that the studied superficial medullary structures play an important role for the maintenance of tonic vasomotor neuron activity, especially renal.
在水合氯醛麻醉的猫身上，研究了在延髓腹侧对应于吻侧化学感受器区尾端部分和中间区的受限区域局部应用药物所引起的心血管调节。在这些结构上局部应用γ-氨基丁酸（GABA）或甘氨酸会导致血压下降、心动过缓、肾脏和骨骼肌血管舒张以及呼吸抑制。应用毒扁豆碱时，除了轻微的心动过速外，会出现类似的反应。应用GABA会使对去除动脉压力感受器抑制（颈动脉闭塞）的反射性血管收缩反应明显减弱，尤其是在肾脏，并且会使对压力感受器刺激的反射性肾血管舒张消失。这些发现表明，应用GABA会导致紧张性血管运动神经元活动普遍减弱，对于肾血管运动神经元而言，几乎会使其停止活动。应用硝酸甲基阿托品会导致血压升高、骨骼肌和肾脏的外周阻力增加以及对颈动脉闭塞的肾血管收缩反应强烈增强。结果表明，所研究的延髓浅表结构对于维持紧张性血管运动神经元活动，尤其是肾脏的活动，起着重要作用。
