Net Influx and Efflux of 22Na in Erythrocytes from Normotensive Offspring of Patients with Essential Hypertension

Abstract

Fresh erythrocytes from 35 young normotensive individuals (20 males), the offspring of patients with essential hypertension (EH), and from 24 normotensive controls (14 males) were incubated at 37.degree. C in an isotonic buffer with 22Na. After 80 min, the net influx (net accumulation) of 22Na was not significantly different in either group, but after 140 min it was significantly higher (8.2%, P < 0.01) in erythrocytes from male offspring as opposed to male controls. After both 80 and 140 min of incubation, the net influx of 22Na was significantly higher in males than in females in the respective groups. During a 60 min period the net efflux of 22Na from preincubated (180 min) erythrocytes in 14 males in the offspring group was not significantly different from that found in 10 male controls. Apparently little differences exist in vitro between offspring and controls in the unidirectional fluxes across the membrane. The difference between the male groups in the net influx after 140 min indicate a higher Na content in the intracellular space in the offspring group, an assumption subsequently verified in a follow-up. The net influx of 22Na after 140 min was significantly correlated (r = 0.58, P < 0.05) to total plasma aldosterone in male controls, but not in the offspring. No differences in the mean concentrations of total aldosterone, plasma and urinary electrolytes or in serum .gamma.-glutamyl transferase were noted between offspring and controls. Abnormal cellular handling of Na at least in the male offspring of patients with EH for at least 2 generations may be an important predisposing factor for EH.