Influence of pulmonary blood flow and O2 flux on DO2 in avian lungs

Respiration Physiology
S C Hempleman, F L Powell


O2 diffusing capacity (DO2) was measured in anesthetized, unidirectionally ventilated ducks during hypercapnic hypoxia. DO2 averaged 78.2 mumol X (min X Torr)-1. This value increased to 97.3 mumol X (min X Torr)-1 after correction for ventilation-perfusion inequality. DO2 increased when pulmonary O2 exchange (MO2) and pulmonary blood flow (Q) were increased by either 2,4 dinitrophenol (DNP,ca. 5 mg/kg i.v.) or temporary unilateral pulmonary artery occlusion (TUPAO). DO2 increased with MO2 42.4 mumol X (mmol X Torr)-1 (R = 0.664), and with Q 80.3 mumol X (L X Torr)-1 (R = 0.895). Since there is evidence against expansion of membrane diffusing capacity through recruitment and distention of pulmonary capillaries in avian lungs, we suggest that the close coupling of DO2 to Q reflects a reduction of functional lung heterogeneity at higher blood flows, perhaps due to better matching of V to D, or D to Q.


Sep 1, 1988·Respiration Physiology·S C Hempleman, A T Gray
Sep 1, 1990·Respiration Physiology·J A EstavilloR E Burger
Jan 1, 1993·Respiration Physiology·F L Powell, S C Hempleman
Mar 20, 2009·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·J Q PilarskiS C Hempleman
Jun 18, 2014·Research in Veterinary Science·E M PritchettA L Johnson
Mar 1, 1990·Pharmacology, Biochemistry, and Behavior·R A Hughes
Nov 6, 2007·Respiratory Physiology & Neurobiology·Rebecca R WatsonJohn B West
Mar 16, 2004·News in Physiological Sciences : an International Journal of Physiology Produced Jointly by the International Union of Physiological Sciences and the American Physiological Society·F L Powell, Susan R Hopkins
May 1, 1996·Critical Reviews in Food Science and Nutrition·J Chirife, M D Buera

Related Concepts

Hematocrit Procedure
Oxygen Consumption
Pulmonary Circulation
Pulmonary Diffusing Capacity
Ventilation-Perfusion Ratio

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