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Central Reflex Effects of Hypoxia on Muscle Oxygenation

  • D. L. Bredle
  • C. K. Chapler
  • S. M. Cain
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 248)

Abstract

We postulated that whole body hypoxia causes O2 demand to increase in skeletal muscle because hypoxia stimulates sympathetic release of catecholamines which are calorigenic. Such an effect would be masked in a typical hypoxia model in which regional O2 uptake would also be limited by O2 availability. Our first goal in these experiments was to circumvent this difficulty and demonstrate that our postulate was correct. The second goal for these experiments was to determine the strength and duration of centrally mediated vasoconstriction in muscle in the absence of local hypoxia. Previous studies (Cain and Chapler, 1979; 1980) have shown that muscle vascular resistance increased less than 20% in severe whole body hypoxia and that after 30 min of hypoxia, local dilatory factors had overcome any vasoconstriction. To meet both these goals, we maintained normoxic regional perfusion to hindlimb skeletal muscles of anesthetized dogs by use of a pump and membrane oxygenator while ventilating the animal with an hypoxic gas mixture. To show the role of innervation in regional hypoxic reactions, we compared metabolic and hemodynamic events in innervated and denervated limbs.

Keywords

Hypoxic Hypoxia Succinylcholine Chloride Global Hypoxia Calorigenic Effect Intact Innervation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Bredle, D.L., Chapler, C.K., and S.M. Cain, 1988a, Metabolic and circulatory responses of normoxic skeletal muscle to whole body hypoxia, J. Appl. Physiol, (in press).Google Scholar
  2. Bredle, D.L., Chapler, CK., and S.M. Cain, 1988b, Metabolic and circulatory responses of normoxic skeletal muscle to whole body hypoxia and a-blockade. Physiologist (abstract, in press).Google Scholar
  3. Cain, S.M. and Chapler, C.K., 1979, Oxygen extraction by canine hindlimb during hypoxic hypoxia, J. Appl. Physiol. 46:1023–1028.PubMedGoogle Scholar
  4. Cain, S.M. and Chapler, C.K., 1980, O2 extraction by canine hindlimb during α-adrenergic blockade and hypoxic hypoxia, J. Appl. Physiol. 48:630–635.PubMedGoogle Scholar
  5. Clonninger, G.L. and Green, H.D., 1955, Pathways taken by the sympathetic chain to the vasculature of the hindleg muscles of the dog, Am. J. Physiol. 181:258–262.PubMedGoogle Scholar
  6. Sylvester, J.T., Scharf, S.M., Gilbert, R.D., Fitzgerald, R.S., and Traystman, R.J., 1979, Hypoxic and CO hypoxia in dogs: hemodynamics, carotid reflexes, and catecholamines, Am. J. Physiol. 236:H22–H28.PubMedGoogle Scholar

Copyright information

© Plenum Press, New York 1989

Authors and Affiliations

  • D. L. Bredle
    • 1
  • C. K. Chapler
    • 2
  • S. M. Cain
    • 1
  1. 1.Dept. of Physiology and BiophysicsUniv. of Alabama at BirminghamBirminghamUSA
  2. 2.Dept. of PhysiologyQueen’s UnivKingstonCanada

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