Interaction of O2 and CO2 in sustained exercise hyperemia of canine skeletal muscle. Am J Physiol 1975 Jul;229(1):28-33
Date
07/01/1975Pubmed ID
238405DOI
10.1152/ajplegacy.1975.229.1.28Scopus ID
2-s2.0-0016590594 (requires institutional sign-in at Scopus site) 15 CitationsAbstract
The relative contribution of O2 and CO2 to the metabolic control of blood flow in long-term exercise was examined in the denervated gracilis muscle of the anesthetized dog. The data show that 1) on initiation of heavy exercise, the effluent blood PO2 and pH fall markedly and then rise slowly but remain depressed relative to control during 60 min of exercise hyperemia, while the initial increases in [K+] and osmolality rapidly approach and eventually reach preexercise levels. 2) The enhanced vasodilator activity of venous blood from exercising muscle is attenuated when effluent blood PO2 or pH is corrected to preexercise levels; it is completely abolished when both are corrected. 3) Induced reduction PO2 or pH in the arterial inflow, and thus venous outflow, of resting muscle produces a fall in resistance; simultaneous reductions of both to levels seen in heavy exercise produce a fall in resistance to near that observed during exercise. Since the enhanced vasodilator activity of venous blood from the contracting muscle was abolished by simultaneous correction of the PO2 and pH, it seems likely that these factors, acting directly or indirectly, are the principal chemicals responsible for the maintenance of the vasodilation seen in canine skeletal muscle during heavy exercise.
Author List
Stowe DF, Owen TL, Anderson DK, Haddy FJ, Scott JBAuthor
David F. Stowe MD, PhD Professor in the Anesthesiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsBlood Flow Velocity
Blood Pressure
Carbon Dioxide
Dogs
Female
Hydrogen-Ion Concentration
Hyperemia
Male
Muscle Contraction
Muscles
Osmolar Concentration
Oxygen
Physical Exertion
Potassium
Regional Blood Flow
Vascular Resistance
