Microelectrode Studies of Facilitated O2 Transport Across Hemoglobin and Myoglobin Layers
Kreuzer and Hoofd (1987) recently reviewed the experimental evidence, theoretical framework and physiological significance for facilitated O2 transport by hemoglobin in the red blood cell and by myoglobin in heart and red skeletal muscle. It is now well accepted that these vital biological proteins enhance tissue O2 delivery by carrier-mediated transport. However, many mechanistic details are not fully understood or their importance in vivo have not been completely evaluated. Much of the previous research during the past 30 years has been conducted with flat layers of carrier protein solutions subjected to known O2 concentration gradients in diffusion chambers. Facilitated O2 transport theory predicts how PO2 will vary with distance across the layer. In the present study, we measured PO2 profiles with recessed cathode microelectrodes (Whalen et al, 1967) across ca. 500 μm layers of aqueous solutions containing either hemoglobin or myoglobin. To our knowledge, there have been no previous attempts to evaluate facilitated O2 transport theory by actually measuring PO2 profiles in carrier protein solutions.
KeywordsTransport Theory Equilibrium Curve Gracilis Muscle Diffusion Chamber Damkohler Number
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