|
|
||||||||
Journal of Applied Physiology, Vol 63, Issue 2 726-732, Copyright © 1987 by American Physiological Society
ARTICLES |
C. E. King, S. L. Dodd and S. M. Cain
Department of Physiology and Biophysics, University of Alabama, Birmingham 35294.
The consequences of a decreased O2 supply to a contracting canine gastrocnemius muscle preparation were investigated during two forms of hypoxia: hypoxic hypoxia (HH) (n = 6) and CO hypoxia (COH) (n = 6). Muscle O2 uptake, blood flow, O2 extraction, and developed tension were measured at rest and at 1 twitch/s isometric contractions in normoxia and in hypoxia. No differences were observed between the two groups at rest. During contractions and hypoxia, however, O2 uptake decreased from the normoxic level in the COH group but not in the HH group. Blood flow increased in both groups during hypoxia, but more so in the COH group. O2 extraction increased further with hypoxia (P less than 0.05) during concentrations in the HH group but actually fell (P less than 0.05) in the COH group. The O2 uptake limitation during COH and contractions was associated with a lesser O2 extraction. The leftward shift in the oxyhemoglobin dissociation curve during COH may have impeded tissue O2 extraction. Other factors, however, such as decreased myoglobin function or perfusion heterogeneity must have contributed to the inability to utilize the O2 reserve more fully.
This article has been cited by other articles:
![]() |
J. Gonzalez-Alonso, D. B. Olsen, and B. Saltin Erythrocyte and the Regulation of Human Skeletal Muscle Blood Flow and Oxygen Delivery: Role of Circulating ATP Circ. Res., November 29, 2002; 91(11): 1046 - 1055. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. S. Richardson, E. A. Noyszewski, B. Saltin, and J. Gonzalez-Alonso Effect of mild carboxy-hemoglobin on exercising skeletal muscle: intravascular and intracellular evidence Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2002; 283(5): R1131 - R1139. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. E. King-VanVlack, J. D. Mewburn, C. K. Chapler, and P. H. MacDonald Endothelial modulation of skeletal muscle blood flow and VO2 during low- and high-intensity contractions J Appl Physiol, February 1, 2002; 92(2): 461 - 468. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Davis and S. Kanatous Convective oxygen transport and tissue oxygen consumption in Weddell seals during aerobic dives J. Exp. Biol., January 5, 1999; 202(9): 1091 - 1113. [Abstract] [PDF] |
||||
![]() |
S. E. Curtis, T. A. Walker, W. E. Bradley, and S. M. Cain Raising P50 increases tissue PO2 in canine skeletal muscle but does not affect critical O2 extraction ratio J Appl Physiol, November 1, 1997; 83(5): 1681 - 1689. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |