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

Steven C Hempleman, Frank L. Powell

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

O2 diffusing capacity (DO2) was measured in anesthetized, unidirectionally ventilated ducks during hypercapnic hypoxia. DO2 averaged 78.2 μmol·(min·Torr)-1. This value increased to 97.3 μmol·(min·Torr)-1 after correction for ventilation-perfusion inequality. DO2 increased when pulmonary O2 exchange (MO2) and pulmonary blood flow (Ṁ) 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 μmol·(mmol·Torr)-1 (R=0.664), and with Q̇ 80.3 μmol·(L·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 Q̇ reflects a reduction of functional lung heterogeneity at higher blood flows, perhaps due to better matching of V̇ to D, or D to Q̇.

Original languageEnglish (US)
Pages (from-to)285-292
Number of pages8
JournalRespiration Physiology
Volume63
Issue number3
DOIs
StatePublished - 1986
Externally publishedYes

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Keywords

  • 2,4 dinitrophenol
  • Cross current
  • Duck
  • Exercise
  • Gas exchange
  • Hypoxia
  • Lung inhomogeneity
  • Oxygen diffusing capacity
  • Ventilation/perfusion ratio

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine

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