Estimation of the Transfer Coefficients of Oxygen and Carbon Monoxide in the Boundary of Human and Chicken Red Blood Cells by a Microphotometric Method

Abstract

A microphotometric method to measure the reaction rates of O₂ and CO was developed by Mochizuki et al. (1973) for the purpose of measurements in a single red blood cell (RBC). To date, the rates of oxygenation, deoxygenation, Bohr-on and Bohr-off shift, and replacement reaction of O₂ by CO have been studied by this method (Mochizuki et al., 1973; Tazawa et al., 1974; Tazawa and Mochizuki, 1976; Tazawa et al., 1976). However, since the reaction rates were much influenced by the thickness of the liquid layer remaining around the RBC, the definite reaction processes of O₂ and CO with RBCs have not yet been established. In the present study, to clarify the kinetics of the diffusion and reaction processes of O₂ and CO in the RBC and the RBC boundary, we measured reaction rates of O₂ and CO in human and chicken RBCs and computed numerical solutions of partial differential equations of diffusion of O₂ and CO. Then, by comparing the two results, we estimated the diffusion rate factor across the boundary layer including the RBC membrane, i.e., the transfer coefficients of O₂ and CO (ηo₂ and ηco).