Significant blood resistance to nitric oxide transfer in the lung


BORLAND C. D. R. , DUNNINGHAM H., BOTTRILL F., VUYLSTEKE A., Yilmaz C. , DANE D. M. , ...More

JOURNAL OF APPLIED PHYSIOLOGY, vol.108, no.5, pp.1052-1060, 2010 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 108 Issue: 5
  • Publication Date: 2010
  • Doi Number: 10.1152/japplphysiol.00904.2009
  • Journal Name: JOURNAL OF APPLIED PHYSIOLOGY
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.1052-1060
  • Keywords: lung diffusing capacity, membrane diffusing capacity, carbon monoxide, lung diffusing capacity for carbon monoxide, lung diffusing capacity for nitric oxide, gas exchange, membrane oxygenator, exchange transfusion, bovine hemoglobin glutamer, blood substitute, MEMBRANE DIFFUSING-CAPACITY, CARBON-MONOXIDE, RED-CELL, CO TRANSFER, PULMONARY MEMBRANE, CHEMICAL-REACTION, HUMAN HEMOGLOBIN, OXYGEN CARRIER, TISSUE VOLUME, NO

Abstract

Borland CD, Dunningham H, Bottrill F, Vuylsteke A, Yilmaz C, Dane DM, Hsia CC. Significant blood resistance to nitric oxide transfer in the lung. J Appl Physiol 108: 1052-1060, 2010. First published February 11, 2010; doi:10.1152/japplphysiol.00904.2009.-Lung diffusing capacity for nitric oxide (DL(NO)) is used to measure alveolar membrane conductance (DM(NO)), but disagreement remains as to whether DM(NO) = DL(NO), and whether blood conductance (theta(NO)) = infinity. Our previous in vitro and in vivo studies suggested that (theta(NO)) = infinity. We now show in a membrane oxygenator model perfused with whole blood that addition of a cell-free bovine hemoglobin (Hb) glutamer-200 solution increased diffusing capacity of the circuit (D) for NO (DNO) by 39%, D for carbon monoxide (DCO) by 24%, and the ratio of DNO to DCO by 12% (all P < 0.001). In three anesthetized dogs, DL(NO) and DL(CO) were measured by a rebreathing technique before and after three successive equal volume-exchange transfusions with bovine Hb glutamer-200 (10 ml/kg each, total exchange 30 ml/kg). At baseline, DL(NO)/DL(CO) = 4.5. After exchange transfusion, DL(NO) rose 57 +/- 16% (mean +/- SD, P = 0.02) and DL(NO)/DL(CO) = 7.1, whereas DL(CO) remained unchanged. Thus, in vitro and in vivo data directly demonstrate a finite theta(NO). We conclude that the erythrocyte and/or its immediate environment imposes considerable resistance to alveolar-capillary NO uptake. DL(NO) is sensitive to dynamic hematological factors and is not a pure index of conductance of the alveolar tissue membrane. With successive exchange transfusion, the estimated in vivo theta(NO) [5.1 ml NO.(ml blood.min.Torr)(-1)] approached 4.5 ml NO.(ml blood.min.Torr)(-1), which was derived from in vitro measurements by Carlsen and Comroe (J Gen Physiol 42: 83-107, 1958). Therefore, we suggest use of theta(NO) = 4.5 ml NO.(min.Torr.ml blood)(-1) for calculation of DM(NO) and pulmonary capillary blood volume from DL(NO) and DL(CO).