Net influx and efflux of 22Na in erythrocytes from normotensive offspring of patients with essential hypertension.

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 degrees 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 less than 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-minute 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. These findings could indicate that little differences exists in vitro between offspring and controls in the undirectional fluxes across the membrane. The difference between the male groups in the net influx after 140 min could indicate a higher Na content in the intracellular space in the offspring group, as assumption subsequently verified in a follow-up. The net influx of 22Na after 140 min was significantly correlated (R=0.58, p less than 0.05) to total plasma aldosterone 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 sodium at least in the male offspring of patients with EH for at least two generations may be an important predisposing factor for EH.