Linnarsson D, Hesser C M
J Appl Physiol Respir Environ Exerc Physiol. 1978 Nov;45(5):756-61. doi: 10.1152/jappl.1978.45.5.756.
The effects of hyberbaric nitrogen on the responses of ventilation and central inspiratory activity (CIA) to progressive hypercapnia were studied in eight subjects rebreathing a) O2 at an ambient pressure of 1.3 bar (control), and b) air at 6.1 bar (PO2 = 1.3 bar, PN2 = 4.8 bar). Inspiratory occlusion pressure (P0.1), pulmonary ventilation, and end-tidal PCO2 were used for the computation of individual CIA and ventilatory CO2 response curves. Increasing the inspired PN2 to 4.8 bar caused, on the average, a 40% increase of P0.1 at PCO2 = 50 Torr, whereas the slope of the ventilatory CO2 response curve was reduced by 39%. It was concluded that, at raised air and nitrogen pressures, CIA is increased, although not sufficiently to prevent a reduction of ventilation brought about by the increased gas density and consequent increase in airway resistance. The increased airway resistance is thought to be responsible for the increase in CIA by causing a reflex stimulation of the respiratory centers.
在8名受试者中，研究了高压氮对通气反应以及中枢吸气活动（CIA）对渐进性高碳酸血症反应的影响。受试者在再呼吸时的环境压力为：a）1.3巴下的氧气（对照），以及b）6.1巴下的空气（PO2 = 1.3巴，PN2 = 4.8巴）。吸气阻断压力（P0.1）、肺通气和呼气末PCO2用于计算个体CIA和通气CO2反应曲线。将吸入的PN2增加到4.8巴时，在PCO2 = 50托时，P0.1平均增加40%，而通气CO2反应曲线的斜率降低了39%。得出的结论是，在升高的空气和氮气压力下，CIA增加，尽管增加幅度不足以防止因气体密度增加和随之而来的气道阻力增加所导致的通气减少。气道阻力增加被认为是通过对呼吸中枢的反射性刺激导致CIA增加的原因。
