|
|
||||||||
AJP - Heart and Circulatory Physiology, Vol 272, Issue 3 1106-H1112, Copyright © 1997 by American Physiological Society
ARTICLES |
T. B. Bentley and R. N. Pittman
Department of Physiology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0551, USA.
A mathematical analysis by Popel et al. [Am. J. Physiol. 256 (Heart Circ. Physiol. 25): H921-H924, 1989] of in vivo data on arteriolar O2 loss suggested that Krogh's diffusion coefficient (KO2 = alpha x DO2, where DO2 is the O2 diffusion coefficient and alpha is the tissue O2 solubility) in vivo could be an order of magnitude larger than that calculated from DO2 values measured in vitro at 22 degrees C and extrapolated to 37 degrees C. In this study, to eliminate potential extrapolation errors, we used a miniature hyperbaric chamber with 1-2 atm of O2 to maintain tissue oxygenation and allow DO2 measurements directly at 37 degrees C while using a non-steady-state technique. The need for metabolic poisons that had been required by earlier experimental techniques was thereby eliminated. DO2 measured directly at 37 degrees C (2.42 x 10(-5) cm2/s) and the increase with temperature of DO2 between 30 and 41 degrees C (4.61%/degrees C) were unexpectedly higher than the values we found at lower temperatures. Oxygen consumption was also higher than expected at 37 degrees and 40 degrees C. An analysis of the activation energy for DO2 suggests that at higher temperatures there is a change in the diffusion pathway from that existing at lower temperatures, perhaps caused by phase transitions in the lipid membranes.
This article has been cited by other articles:
![]() |
E. Takahashi Anoxic cell core can promote necrotic cell death in cardiomyocytes at physiological extracellular PO2 Am J Physiol Heart Circ Physiol, June 1, 2008; 294(6): H2507 - H2515. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. J. van der Laarse, A. L. des Tombe, B. J. van Beek-Harmsen, M. B. E. Lee-de Groot, and R. T. Jaspers Krogh's diffusion coefficient for oxygen in isolated Xenopus skeletal muscle fibers and rat myocardial trabeculae at maximum rates of oxygen consumption J Appl Physiol, December 1, 2005; 99(6): 2173 - 2180. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. G. TSAI, P. C. JOHNSON, and M. INTAGLIETTA Oxygen Gradients in the Microcirculation Physiol Rev, July 1, 2003; 83(3): 933 - 963. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. R. Mitchell, M. B. Harris, A. R. Cordaro, and J. W. Starnes Effect of body temperature during exercise on skeletal muscle cytochrome c oxidase content J Appl Physiol, August 1, 2002; 93(2): 526 - 530. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Vadapalli, R. N. Pittman, and A. S. Popel Estimating oxygen transport resistance of the microvascular wall Am J Physiol Heart Circ Physiol, August 1, 2000; 279(2): H657 - H671. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |