Comparative aspects of Na +-K + and Ca 2+-Mg 2+ ATPase in erythrocyte membranes of various mammals

Abstract

This work is a comparative study of Na +-K + and Ca 2+-Mg 2+ ATPase associated with the erythrocyte plasma membranes in different mammals. The method used to test the activity of these enzymes is based on quantitative measurements of ADP released during the reaction with HPLC: the Chromatographie type is an Ion-Pair Reversed Phase. We have found that the levels of Ca 2+ stimulated ATPase are higher than those of Na +-K + ATPase in red blood cells of all the different mammalian species, with the only exception being lamb erythrocytes where the values of both the ATPase activités are almost equal. The results obtained have shown different levels of the Na +-K + ATPase as well as of the Ca 2+ stimulated ATPase activity. Furthermore, we have made a comparative study of the ATPase activities in different red blood cells with specific reference to the optimum pH, thermostability, kinetic characteristics and the inhibitory effects of ouabain and vanadate.