Takahashi E, Menon A S, Kato H, Slutsky A S, Phillipson E A
Department of Medicine, University of Toronto, Ontario, Canada.
Respir Physiol. 1990 Jan;79(1):45-55. doi: 10.1016/0034-5687(90)90059-8.
The role of respiratory oscillations of PaCO2 (CO2 oscillations) in the regulation of expiratory duration (TE) was examined in eight anesthetized dogs by measuring instantaneous changes of arterial pH during the respiratory cycle with a catheter-tip ISFET (ion-sensitive field effect transistor) pH electrode. Steady-state changes in arterial pH oscillation were induced by vagotomy, which increased the amplitude of pH oscillation from 0.014 +/- 0.002 (mean +/- SEM) to 0.058 +/- 0.006 units (P less than 0.001), and prolonged TE from 5.12 +/- 0.56 to 9.99 +/- 1.11 sec (P less than 0.005) with little change in average pH (0.021 +/- 0.011 units, P = 0.12). Vagotomy also reversed the phase relationship between arterial pH oscillation at the carotid bodies and tidal ventilation, such that pH rose during early expiration, rather than falling as occurred in the intact state. When the within-breath oscillation of arterial pH was transiently reduced by having the vagotomized dogs inspire a single breath of CO2 enriched air, TE of the same breath was shortened in proportion to the reduction in amplitude of pH oscillation (r = 0.72, P less than 0.001), rather than in proportion to changes in the average pH of the test breath (r = 0.44). The results indicate that the profile of within-breath oscillation of PaCO2 (phase relationship and amplitude) can exert an important influence on TE, and may in part account for the prolongation of TE following vagotomy.
通过使用导管尖端离子敏感场效应晶体管（ISFET）pH电极测量呼吸周期中动脉pH的瞬时变化，在八只麻醉犬中研究了动脉血二氧化碳分压的呼吸振荡（二氧化碳振荡）在呼气持续时间（TE）调节中的作用。迷走神经切断术诱导了动脉pH振荡的稳态变化，其将pH振荡幅度从0.014±0.002（平均值±标准误）增加到0.058±0.006单位（P<0.001），并将TE从5.12±0.56延长至9.99±1.11秒（P<0.005），而平均pH变化很小（0.021±0.011单位，P=0.12）。迷走神经切断术还逆转了颈动脉体处动脉pH振荡与潮气量通气之间的相位关系，使得pH在呼气早期上升，而不是像完整状态下那样下降。当迷走神经切断的犬吸入一口气富含二氧化碳的空气，使呼吸内动脉pH振荡暂时降低时，同一呼吸的TE与pH振荡幅度的降低成比例缩短（r=0.72，P<0.001），而不是与测试呼吸的平均pH变化成比例（r=0.44）。结果表明，动脉血二氧化碳分压呼吸内振荡的特征（相位关系和幅度）可对TE产生重要影响，并且可能部分解释了迷走神经切断术后TE的延长。
