Branco L G, Glass M L, Hoffmann A
Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brazil.
Respir Physiol. 1992 Feb;87(2):195-204. doi: 10.1016/0034-5687(92)90059-6.
Central chemoreceptor drive to breathing was studied in unanesthetized toads, equipped with face masks to measure pulmonary ventilation and arterial catheters to analyze blood gases. Two series of experiments were performed. Expt. 1: The fourth cerebral ventricle was perfused with solutions of mock CSF, adjusted to stepwise decreasing pH values. Concomitant perfusion-induced increases of pulmonary ventilation, pHa and PaO2 were measured. Expt. 2: Inspiration of hypercapnic gas mixtures was applied to stimulate both central and peripheral chemoreceptors. Subsequently, only peripheral chemoreceptors were stimulated. This was accomplished by repeating the hypercapnic conditions while the fourth ventricle was perfused with mock CSF at pH 7.7. This procedure reduced the slope of the ventilatory response curve by about 80%. Taken together, the experiments suggest a highly dominant role of central chemoreceptors in the ventilatory acid-base regulation of the toad.
在未麻醉的蟾蜍中研究了中枢化学感受器对呼吸的驱动作用，这些蟾蜍配备了用于测量肺通气的面罩和用于分析血气的动脉导管。进行了两个系列的实验。实验1：用模拟脑脊液溶液灌注第四脑室，将其pH值逐步调至降低。测量伴随灌注引起的肺通气、动脉血pH值（pHa）和动脉血氧分压（PaO2）的增加。实验2：吸入高碳酸气体混合物以刺激中枢和外周化学感受器。随后，仅刺激外周化学感受器。这是通过在第四脑室用pH 7.7的模拟脑脊液灌注时重复高碳酸条件来实现的。该程序使通气反应曲线的斜率降低了约80%。综合来看，这些实验表明中枢化学感受器在蟾蜍通气酸碱调节中起高度主导作用。
