Intracellular Calcium: Lack of Effect on Ovine Red Cells

Abstract

Normal mammalian erythrocytes contain very small amounts of Ca2+. When erythrocytes from most mammals are subjected to ionophore-induced Ca2+ accumulation, extensive morphologic and metabolic damage occurs. This is not true of red cells from adult sheep; these cells appear to be totally unresponsive to sudden increases in intracellular Ca2+. Red cells from newborn lambs are responsive to Ca2+ influx and gradually become unresponsive during maturation of the animal. Although the precise reasons for the lack of response of adult sheep erythrocytes to Ca2+ accumulation is unknown, this system may provide a valuable model for the dissection of the various effects of Ca2+ upon cells and cell membranes.