Chapman R W, Santiago T V, Edelman N H
J Appl Physiol Respir Environ Exerc Physiol. 1982 Jul;53(1):212-7. doi: 10.1152/jappl.1982.53.1.212.
Vagally mediated reflexes play an important role in the generation of respiratory responses to various stimuli. This study examined the role of vagally mediated mechanisms in the generation of the respiratory responses to progressive brain hypoxia secondary to carboxyhemoglobinemia (HbCO 0-55%) in six unanesthetized goats. Ventilation, respiratory cycle timing, and the lung inflation reflex were measured before and during CO inhalation in intact and bilaterally vagotomized animals. Our results indicate that vagal reflexes contribute a small magnitude of the hyperpnea caused by carboxyhemoglobinemia. Furthermore, in contrast to that reported for CO2 inhalation, the tachypneic nature of the ventilatory response to CO is not a vagally mediated phenomenon. CO inhalation had a biphasic influence on the strength of the lung inflation reflex measured as the ratio of inspiratory time during occlusion (TIoccl) to inspiratory time of the preceding spontaneous breath (TIspont). At HbCO levels of 35%, TIoccl/TIspont was enhanced, whereas at HbCO levels of 55% of ratio fell to unity, indicating abolition of the reflex. After vagotomy, this ratio was unity at all levels of carboxyhemoglobinemia.
迷走神经介导的反射在对各种刺激产生呼吸反应中起重要作用。本研究在六只未麻醉的山羊中，考察了迷走神经介导机制在因碳氧血红蛋白血症（HbCO 0 - 55%）继发的进行性脑缺氧所产生的呼吸反应中的作用。在完整和双侧迷走神经切断的动物吸入CO之前和期间，测量通气、呼吸周期时间和肺充气反射。我们的结果表明，迷走神经反射对碳氧血红蛋白血症引起的呼吸急促作用较小。此外，与吸入CO2的情况不同，对CO通气反应的呼吸急促性质不是迷走神经介导的现象。吸入CO对以阻断期间吸气时间（TIoccl）与前一次自主呼吸吸气时间（TIspont）之比衡量的肺充气反射强度有双相影响。在HbCO水平为35%时，TIoccl/TIspont增强，而在HbCO水平为55%时，该比值降至1，表明反射消失。迷走神经切断后，在所有碳氧血红蛋白血症水平下该比值均为1。
