Kuwana S, Natsui T
J Physiol. 1981 Sep;318:223-37. doi: 10.1113/jphysiol.1981.sp013860.
Phrenic nerve discharges were recorded as an output of respiratory activity in anaesthetized, vagotomized cats immobilized by gallamine and artificially ventilated with room air. 2. With the carotid sinus nerve (c.s.n.) intact or denervated, PcO2 threshold levels (Pth, CO2) were determined at arterial pH, varied between 7.0 and 7.6 ([H+] 25-100 nM) by successive intravenous infusions of 0.5 N-HCl or 1.0 M-NaHCO3. Ventilation was increased stepwise to induce a successive decrease in end-tidal PCO2. Pth, CO2 was defined as the level of end-tidal PCO2 at which phrenic discharges ceased. 3. With the c.s.n. intact, Pth, CO2 decreased linearly upon increasing arterial [H+]. The mean regression line, calculated from seven cats, was Pth, CO2 =-0.37 [H+] + 34.33. A similar inverse relationship was observed with the c.s.n. denervated. However, the slope of the regression line was significantly smaller, the mean regression line/eleven cats) being Pth,CO2 =-0.18 [H+]+ 35.06. 4. The relative contributions of arterial [H+] and PCO2 in stimulating the peripheral and central chemoreceptors could be estimated quantitatively. Arterial [H+] appears to be almost equally effective on both peripheral and central chemoreceptors; PCO2 acts exclusively on the central chemoreceptors. 5. Thus, the additive theory regarding the induction of respiratory activity by arterial [H+] and PCO2 was confirmed. In addition, the H+ drive was shown to be able to affect respiratory activity even in the absence of the peripheral chemoreceptors.
在通过加拉明固定并以室内空气进行人工通气的麻醉、迷走神经切断的猫中，记录膈神经放电作为呼吸活动的输出。2. 在完整或去神经支配的颈动脉窦神经（c.s.n.）情况下，通过连续静脉输注0.5N - HCl或1.0M - NaHCO₃，将动脉pH值在7.0至7.6（[H⁺] 25 - 100 nM）之间变化，测定PCO₂阈值水平（Pth, CO₂）。逐步增加通气以诱导呼气末PCO₂连续下降。Pth, CO₂定义为膈神经放电停止时的呼气末PCO₂水平。3. 在c.s.n.完整时，随着动脉[H⁺]增加，Pth, CO₂呈线性下降。由七只猫计算得出的平均回归线为Pth, CO₂ = -0.37[H⁺] + 34.33。在c.s.n.去神经支配时也观察到类似的反比关系。然而，回归线的斜率明显较小，十一只猫的平均回归线为Pth,CO₂ = -0.18[H⁺]+ 35.06。4. 可以定量估计动脉[H⁺]和PCO₂在刺激外周和中枢化学感受器中的相对贡献。动脉[H⁺]对外周和中枢化学感受器似乎几乎同样有效；PCO₂仅作用于中枢化学感受器。5. 因此，关于动脉[H⁺]和PCO₂诱导呼吸活动的相加理论得到证实。此外，即使在外周化学感受器缺失的情况下，H⁺驱动也被证明能够影响呼吸活动。
