Advertisement
Research Article Free access | 10.1172/JCI105548
Department of Physiology, Graduate Division, University of Pennsylvania, Philadelphia, Pa.
Department of Medicine, University of Pennsylvania, Philadelphia, Pa.
†Address requests for reprints to Dr. Richard W. Hyde, Dept. of Physiology, Graduate Division, University of Pennsylvania, Philadelphia, Pa. 19104.
Daland Fellow of the American Philosophical Society.
‡Present address: Dept. of Medicine, University of Michigan Medical School, Ann Arbor, Mich.
§Postdoctoral research fellow, National Institutes of Health.
ǁIsaac Ott Research Fellow and Fellow of the William McCann Research Trust.
Present address: Institute of Diseases of the Chest, Brompton, London, S.W.3, England.
*Submitted for publication June 29, 1966; accepted December 1, 1966.
This work was supported in part by U. S. Public Health Service grant HE 10324-01 and by a grant from the Life Insurance Medical Research Fund.
Find articles by Hyde, R. in: JCI | PubMed | Google Scholar
Department of Physiology, Graduate Division, University of Pennsylvania, Philadelphia, Pa.
Department of Medicine, University of Pennsylvania, Philadelphia, Pa.
†Address requests for reprints to Dr. Richard W. Hyde, Dept. of Physiology, Graduate Division, University of Pennsylvania, Philadelphia, Pa. 19104.
Daland Fellow of the American Philosophical Society.
‡Present address: Dept. of Medicine, University of Michigan Medical School, Ann Arbor, Mich.
§Postdoctoral research fellow, National Institutes of Health.
ǁIsaac Ott Research Fellow and Fellow of the William McCann Research Trust.
Present address: Institute of Diseases of the Chest, Brompton, London, S.W.3, England.
*Submitted for publication June 29, 1966; accepted December 1, 1966.
This work was supported in part by U. S. Public Health Service grant HE 10324-01 and by a grant from the Life Insurance Medical Research Fund.
Find articles by Rynes, R. in: JCI | PubMed | Google Scholar
Department of Physiology, Graduate Division, University of Pennsylvania, Philadelphia, Pa.
Department of Medicine, University of Pennsylvania, Philadelphia, Pa.
†Address requests for reprints to Dr. Richard W. Hyde, Dept. of Physiology, Graduate Division, University of Pennsylvania, Philadelphia, Pa. 19104.
Daland Fellow of the American Philosophical Society.
‡Present address: Dept. of Medicine, University of Michigan Medical School, Ann Arbor, Mich.
§Postdoctoral research fellow, National Institutes of Health.
ǁIsaac Ott Research Fellow and Fellow of the William McCann Research Trust.
Present address: Institute of Diseases of the Chest, Brompton, London, S.W.3, England.
*Submitted for publication June 29, 1966; accepted December 1, 1966.
This work was supported in part by U. S. Public Health Service grant HE 10324-01 and by a grant from the Life Insurance Medical Research Fund.
Find articles by Power, G. in: JCI | PubMed | Google Scholar
Department of Physiology, Graduate Division, University of Pennsylvania, Philadelphia, Pa.
Department of Medicine, University of Pennsylvania, Philadelphia, Pa.
†Address requests for reprints to Dr. Richard W. Hyde, Dept. of Physiology, Graduate Division, University of Pennsylvania, Philadelphia, Pa. 19104.
Daland Fellow of the American Philosophical Society.
‡Present address: Dept. of Medicine, University of Michigan Medical School, Ann Arbor, Mich.
§Postdoctoral research fellow, National Institutes of Health.
ǁIsaac Ott Research Fellow and Fellow of the William McCann Research Trust.
Present address: Institute of Diseases of the Chest, Brompton, London, S.W.3, England.
*Submitted for publication June 29, 1966; accepted December 1, 1966.
This work was supported in part by U. S. Public Health Service grant HE 10324-01 and by a grant from the Life Insurance Medical Research Fund.
Find articles by Nairn, J. in: JCI | PubMed | Google Scholar
Published March 1, 1967 - More info
A method for appraising the distribution of diffusing capacity of the lungs (DL) in relationship to pulmonary capillary blood flow ([unk]QC) in normal human subjects was derived from measurements of oxygen diffusing capacity (DLO2) and carbon monoxide diffusing capacity (DLCO) performed during breath holding. This method utilizes the fact that the observed DLO2 is considerably reduced in value if uneven distribution of DL with respect to [unk]QC (uneven DL/[unk]QC) is present. In contrast, DLCO is barely affected by uneven DL/[unk]QC, and from its measured value one can calculate the value DLO2 would have if no uneven DL/[unk]QC were present (true DLO2). Once observed DLO2 and true DLO2 are known, the degree of uneven DL/[unk]QC in the lung can be calculated.
In five normal, resting, sitting subjects average values for true DLO2 were 57 ml per (minute × mm Hg), and the directly measured DLO2 was 33 ml per (minute × mm Hg). These values could be explained if one-half of total [unk]QC were distributed to approximately 15% of total DL.
These measurements did not permit the determination of the alveolar to end capillary O2 gradient, but calculations demonstrate that an important factor in determining its size may be the pattern of uneven DL/[unk]QC present in the lungs. Estimations of the alveolar-end capillary O2 gradient from measurements of DLCO or DLO2 that do not take into account uneven DL/[unk]QC may underestimate its size.
Images.