Hyde R W, Geigel E J, Olszowka A J, Krasney J A, Forster R E, Utell M J, Frampton M W
Department of Medicine, University of Rochester School of Medicine and Dentistry, New York 14642, USA.
J Appl Physiol (1985). 1997 Apr;82(4):1290-6. doi: 10.1152/jappl.1997.82.4.1290.
Exercise and inflammatory lung disorders such as asthma and acute lung injury increase exhaled nitric oxide (NO). This finding is interpreted as a rise in production of NO by the lungs (VNO) but fails to take into account the diffusing capacity for NO (DNO) that carries NO into the pulmonary capillary blood. We have derived equations to measure VNO from the following rates, which determine NO tension in the lungs (PL) at any moment from 1) production (VNO); 2) diffusion, where DNO(PL) = rate of removal by lung capillary blood; and 3) ventilation, where V A(PL)/(PB - 47) = the rate of NO removal by alveolar ventilation (V A) and PB is barometric pressure. During open-circuit breathing when PL is not in equilibrium, d/dt PL[V(L)/ (PB - 47)] (where V(L) is volume of NO in the lower airways) = VNO - DNO(PL) - V A(PL)/(PB - 47). When PL reaches a steady state so that d/dt = 0 and V A is eliminated by rebreathing or breath holding, then PL = VNO/DNO. PL can be interpreted as NO production per unit of DNO. This equation predicts that diseases that diminish DNO but do not alter VNO will increase expired NO levels. These equations permit precise measurements of VNO that can be applied to determining factors controlling NO production by the lungs.
运动以及哮喘和急性肺损伤等炎性肺部疾病会增加呼出一氧化氮（NO）的含量。这一发现被解释为肺部一氧化氮生成量（VNO）增加，但未考虑将NO输送到肺毛细血管血液中的一氧化氮扩散能力（DNO）。我们推导了一些方程，用于根据以下速率来测量VNO，这些速率可随时确定肺部的NO张力（PL）：1）生成速率（VNO）；2）扩散速率，其中DNO(PL) = 肺毛细血管血液的清除速率；3）通气速率，其中VA(PL)/(PB - 47) = 肺泡通气（VA）的NO清除速率，PB为大气压力。在开路呼吸且PL未达到平衡时，d/dt PL[V(L)/ (PB - 47)]（其中V(L)是下呼吸道中NO的体积） = VNO - DNO(PL) - VA(PL)/(PB - 47)。当PL达到稳定状态，即d/dt = 0且通过重复呼吸或屏气消除VA时，则PL = VNO/DNO。PL可解释为单位DNO的NO生成量。该方程预测，降低DNO但不改变VNO的疾病会使呼出NO水平升高。这些方程允许精确测量VNO，可用于确定控制肺部NO生成的因素。
