Mechanisms of Increased Tissue Oxygen Delivery Following Release of Arterial Occlusion in Canine Skeletal Muscle and Skin
Tissue oxygen delivery is dependent on the local blood flow and the extent of oxygen extraction. Concerning the intrinsic microvascular control of tissue O2 delivery, a recent system analysis (1) and experimental data (2) suggest that adequate tissue oxygenation is maintained over a wide range of metabolic stresses, the relative contribution of blood flow and O2 extraction to the regulation of tissue O2 delivery being determined by the prevailing venous oxygen level. The previous study (2) has shown that in skeletal muscle perfused with constant pressure, both reactive hyperemia and elevated arteriovenous (A-V) O2 difference contribute to the O2 debt repayment following arterial occlusion when the initial A-V O2 difference is in the normal range. However, at low prevailing A-V O2 difference, increased O2 extraction is the major mechanism by which the tissue repays its O2 debt and the contribution of blood flow is minimal. As the prevailing venous O2 reserve is lowered, the contribution of O2 extraction diminishes and reactive hyperemia becomes more important for the compensation. Thus, the immediate post-occlusion O2 extraction is only slightly elevated or even transiently depressed.
KeywordsArterial Occlusion Reactive Hyperemia Local Blood Flow Anterior Tibial Artery Debt Repayment
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- 2.Granger, H. J., A. H. Goodman, and D. N. Granger. Intrinsic metabolic regulation of blood flow, O2 extraction and tissue O2 delivery in dog skeletal muscle. In: Oxygen Transport to Tissue, ed. by H. I. Bicher, and D. F. Bruley, Plenum Publishing Corporation, New York, 1974, pp. 451–456.Google Scholar