title: Model analysis on alveolar-capillary O2 equilibration during exercise.
abstract: The present article was aimed at determining the alveolar-capillary PO2 difference (deltaP(AcO2)) during exercise. The working hypothesis was that values of the pulmonary NO diffusing capacity can be used to calculate (deltaP(AcO2)) data on the basis of well-known laws of pulmonary gas exchange. For this purpose, we analysed the pertinent data of three studies performed on 35 healthy, non-athletic non-smokers of similar age at seven different exercise intensities. Calculated mean values of alveolar-capillary PO2 difference aggravated from deltaP(AcO2) at rest to (deltaP(AcO2))=18 mmHg at a performance capacity amounting to 90% of the maximum level. Regression analysis revealed (deltaP(AcO2))=0.31* (V O2/V O2 max)2 at a very high significance level (n=7, r=0.999, P<0.0000082). Due to the non-linear increase of (deltaP(AcO2)) with inclining O(2) consumption, our model analysis confirms the opinion that pulmonary diffusion decreasingly determines maximal aerobic power.
authors.affiliation: Department of Physiology, University of Bonn, 53115 Bonn, Germany. h.heller@uni-bonn.de <h.heller@uni-bonn.de>
authors.forename: H
authors.initials: H
authors.lastname: Heller
authors.forename: K-D
authors.initials: KD
authors.lastname: Schuster
mesh_terms: D015444:Exercise; D006801:Humans; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D011650:Pulmonary Alveoli / Q000378:metabolism*
chemical_list: D010100:Oxygen