ATRIAL-NATRIURETIC-FACTOR AS A REGULATOR OF CALCIUM-TRANSPORT MEDIATED BY CA2-ATPASE IN ERYTHROCYTES()

Effects of synthetic analogues of natriuretic factor (AP-II, AP-III, d es-Ser5-des-Ser6-AP II as well as cGMP and activator of kinase C - pho rbol-12-miristat-13acetate) on Ca2+ efflux mediated by Ca -ATPase were studied in intact red blood cells. Calcium concentration in erythrocy te was modified by Ionofore A23187. Maximal activity of Ca2+ efflux wa s registered in Ca2+-loaded cells with the use of Ca selective electro des. After addition of synthetic analogues of atrial natriuretic facto r in low final concentrations the activity of Ca-ATPase in human eryth rocytes was modified. Basing on the results the presence of a receptor to atrial natriuretic factor in the erythrocyte membrane could be sug gested.