[Disorder of erythrocyte membrane calcium binding in hypertension and experimental genetic hypertension].

Under conditions of physiological concentration of free calcium in the incubation medium (Ca2+f = 1.5 mM), the outer surface of the membrane of human and Wistar rat erythrocytes binds 435 +/- and 359 +/- 32 nmol calcium per 1 ml cells, respectively. The external surface of erythrocytes in patients with essential hypertension and in rats with spontaneous hypertension (SHR, Kyoto Wistar) also binds such amounts of calcium. With the concentration of calcium corresponding to its concentration in the intracellular space (Ca2+f less than 1 mcM), the inner membrane surface of eritrocyte ghosts binds only 3.53 +/- 0.16 and 4.28 +/- 0.39 nmol calcium per 1 mg protein of human and rat eritrocyte ghosts, respectively. The noted decrease in the calcium-binding capacity of the inner part of the erythrocyte membrane, being probably a characteristic feature of membrane alteration displayed also in other cellular structure, may determine the changes in tissue sensitivity to the effect of hormones and catecholamines in both types of hypertension.