STUDIES ON THE DIFFERENTIAL MORPHOLOGICAL ALTERATIONS IN HUMAN AND GOAT ERYTHROCYTES AGAINST ATP DEPLETION AND CA2-INDUCED STRESSES()

Erythrocyte membranes obtained from goat exhibited Ca2+/calmodulin-ins ensitive (Ca2+-Mg2+)-ATPase activity and the activity levels were sign ificantly lower as compared to those obtained from human erythrocyte m embranes. Although Ca2+/ionophore A23187-treatment enhanced the intrac ellular Ca2+ levels in both the freshly collected human and goat eryth rocytes, negligible loss of ATP was noticed in goat erythrocytes under such conditions. Also, fluoride, a known metabolic inhibitor, caused a lesser ATP depletion in goat erythrocytes compared to that of human. Goat erythrocytes showed remarkable rigidity to shape change and unli ke human erythrocytes, did not undergo echinocytic formation as a resu lt of metabolic depletion and Ca2+/ionophore A23187-treatments. These studies suggest the participation of (Ca2+-Mg2+)-ATPase-independent me chanism(s) for Ca2+-extrusion