title: Pulmonary diffusion limitation after prolonged strenuous exercise.
abstract: To determine the effect of strenuous prolonged exercise on alveolo-capillary membrane diffusing capacity, 11 marathon runners aged 37 +/- 7 years (mean +/- SD) were studied before and during early recovery (28 +/- 14 min) from a marathon race. Lung capillary blood volume (Vc) and the alveolo-capillary diffusing capacity (Dm) were determined in a one-step maneuver by simultaneous measurements of CO and NO lung transfer (DLCO and DLNO, respectively) using the single breath, breath-holding method. After the race, both DLCO and DLNO were significantly decreased in all subjects (-10.9 +/- 4.8%, P less than 10(-4) and -29.0 +/- 11.1%, P less than 10(-4), respectively). The mean value of the derived DmCO decreased by -29.3 +/- 11.1%, whereas Vc had not entirely returned to control resting value. Although these results do not indicate the detailed mechanism involved, interstitial lung fluid was suspected to accumulate, particularly in alveoli, during the race. We concluded that the high overall work load and the extended duration of the exercise both contributed to a transient change in the structure of the alveolo-capillary membrane thereby affecting the diffusing capacity of the alveolo-capillary membrane.
authors.affiliation: Laboratory of Physiology, Faculty of Medicine, University of Bordeaux, France.
authors.forename: G
authors.initials: G
authors.lastname: Manier
authors.forename: J
authors.initials: J
authors.lastname: Moinard
authors.forename: P
authors.initials: P
authors.lastname: Téchoueyres
authors.forename: N
authors.initials: N
authors.lastname: Varène
authors.forename: H
authors.initials: H
authors.lastname: Guénard
mesh_terms: D000328:Adult; D001824:Body Constitution; D002248:Carbon Monoxide / Q000378:metabolism; D015444:Exercise; D005260:Female; D006339:Heart Rate; D006801:Humans; D008168:Lung / Q000098:blood supply; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D009609:Nitrous Oxide / Q000378:metabolism; D011653:Pulmonary Diffusing Capacity / Q000502:physiology*; D011659:Pulmonary Gas Exchange
chemical_list: D002248:Carbon Monoxide; D009609:Nitrous Oxide