Bainton C R, Richter D W, Seller H, Ballantyne D, Klein J P
J Auton Nerv Syst. 1985 Jan;12(1):77-90. doi: 10.1016/0165-1838(85)90041-4.
Sympathetic activity recorded from cardiac and renal nerves was correlated with phrenic and internal intercostal nerve activity under normocapnea and hypercapnea. Cats were anesthetized with halothane for surgery switching to chloralose for recording. Both vagal and carotid sinus nerves were cut, animals were paralyzed and artificially ventilated. We found that sympathetic activity followed the rhythmic pattern of phrenic nerve discharge fairly closely except in two important respects: first, sympathetic activity was significantly depressed during early inspiration and second, it reached a minimum during post inspiration while phrenic activity was decaying but still active. These effects were accentuated when PACO2 was raised. In one cat early inspiratory depression was the only manifestation of respiratory modulation of sympathetic activity superimposed on an otherwise tonic pattern. In 4 cats sympathetic activity increased in an augmenting fashion in parallel with the augmenting discharge of expiratory alpha motoneurones. We suggest that respiratory-related, excitatory and inhibitory inputs modulate sympathetic activity at the brainstem level. Inspiratory and possibly expiratory interneurones may be the source of activation, and inhibitory inputs may derive from early inspiratory and postinspiratory interneurones. The inhibitory effects may be the only manifestation of respiratory modulation during strong tonic drive of the sympathetic activity.
在正常碳酸血症和高碳酸血症条件下，记录到的心脏和肾神经的交感神经活动与膈神经和肋间内神经活动相关。猫在手术时用氟烷麻醉，记录时改用氯醛糖。切断迷走神经和颈动脉窦神经，使动物麻痹并进行人工通气。我们发现，交感神经活动相当紧密地跟随膈神经放电的节律模式，但有两个重要方面除外：第一，交感神经活动在吸气早期明显受到抑制；第二，它在吸气后达到最小值，而此时膈神经活动正在衰减但仍处于活跃状态。当动脉血二氧化碳分压升高时，这些效应会加剧。在一只猫中，吸气早期抑制是交感神经活动的呼吸调节叠加在原本紧张性模式上的唯一表现。在4只猫中，交感神经活动随着呼气α运动神经元放电的增强而呈增强趋势增加。我们认为，与呼吸相关的兴奋性和抑制性输入在脑干水平调节交感神经活动。吸气神经元以及可能的呼气中间神经元可能是激活的来源，而抑制性输入可能来自吸气早期和吸气后的中间神经元。在交感神经活动的强紧张性驱动期间，抑制效应可能是呼吸调节的唯一表现。
