Skip Navigation LinksHome > January 1995 - Volume 27 - Issue 1 > Muscle blood flow and distribution determine maximal VO2 of...
Medicine & Science in Sports & Exercise:
BASIC SCIENCES/REGULATORY PHYSIOLOGY: Symposium: Mechanisms Which Control [latin capital V with dot above]O2 Near [latin capital V with dot above]O2max: PDF Only

Muscle blood flow and distribution determine maximal VO2 of contracting muscle.


Collapse Box


During repetitive contractions, the VO2 of the dog gastrocnemius-plantaris muscle rose with the contraction frequency up to a maximal value and then decreased as contraction frequency was increased further. PVO2 was constant over most of the contraction frequency range. Reducing perfusion pressure/blood flow reduced [latin capital V with dot above]O2max), with a constant PVO2. During these maneuvers the diffusion conductance, DCO2 ([latin capital V with dot above]O2/PVO2), changed with [latin capital V with dot above]O2. Raising the perfusion pressure/flow with a pump increased [latin capital V with dot above]O2 with a small rise in PVO2 so that DCO2 also increased. Removing tension from the muscle-between contractions elevated [latin capital V with dot above]O2 and DCO2 without a change in perfusion pressure. Hypoxemia decreased [latin capital V with dot above]O2 with a decrease in PVO2,; DCO2 remained constant. A three-compartment mathematical model, based on microsphere measurements of regional flow, was used to illustrate how regional flow variations may exist, and how they are poorly revealed in the mixed whole-muscle venous blood. The model shows [latin capital V with dot above]O2[middle dot]g-1 strongly related to flow. As [latin capital V with dot above]O2[middle dot]-1 increased as [Latin capital letter Q with dot above][middle dot]g-1 Increased, extraction decreased; and DCO2 increased.

(C)1995The American College of Sports Medicine


Article Tools


Article Level Metrics

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.

Connect With Us