Smith C A, Jameson L C, Mitchell G S, Musch T I, Dempsey J A
J Appl Physiol Respir Environ Exerc Physiol. 1984 Jun;56(6):1541-9. doi: 10.1152/jappl.1984.56.6.1541.
We assessed the ventilatory interaction between central [central nervous system (CNS)] and peripheral chemoreceptor stimuli in five awake goats. CNS extracellular fluid (ECF) [H+] was altered with cisterna magna perfusion of mock CSF. Peripheral chemoreceptors were stimulated with three doses of NaCN given intravenously. The resulting dose-response curves were used to assess interaction of the central and peripheral stimuli. The observed interaction was hypoadditive; i.e., the average slope of the NaCN-inspired minute ventilation dose-response line was significantly greater during alkaline perfusion than during acidic perfusion. This correlation can be described by slope = -0.24 (CSF [H+]) + 30.7; r = 0.67 (P less than 0.01). Increased ventilatory responses were accompanied by increases in mean inspiratory flow, tidal volume, and breathing frequency and decreases in expiratory time in response to peripheral chemoreceptor stimulation. Unlike previous reports in anesthetized and denervated animals, in our awake intact goats the ventilatory and tidal volume responses showed no significant dependence on the level of control (pre-NaCN stimulus) inspired minute ventilation. We conclude that the level of [H+] in cerebral ECF exerts a significant reflex-mediated hypoadditive effect on the ventilatory responses to peripheral chemoreceptor stimulation.
我们评估了五只清醒山羊中枢[中枢神经系统（CNS）]与外周化学感受器刺激之间的通气相互作用。通过向小脑延髓池灌注模拟脑脊液来改变中枢细胞外液（ECF）的[H⁺]。通过静脉注射三剂氰化钠刺激外周化学感受器。所得的剂量反应曲线用于评估中枢和外周刺激的相互作用。观察到的相互作用是低加性的；即，在碱性灌注期间，氰化钠激发的分钟通气剂量反应线的平均斜率显著大于酸性灌注期间。这种相关性可用斜率=-0.24（脑脊液[H⁺]）+30.7来描述；r=0.67（P<0.01）。对中枢化学感受器刺激的反应中，通气反应增加伴随着平均吸气流量、潮气量和呼吸频率增加以及呼气时间减少。与之前关于麻醉和去神经动物的报道不同，在我们清醒的完整山羊中，通气和潮气量反应对对照（注射氰化钠前刺激）激发的分钟通气水平没有显著依赖性。我们得出结论，脑ECF中的[H⁺]水平对外周化学感受器刺激的通气反应具有显著的反射介导的低加性效应。
