Erythrocyte cation fluxes in essential hypertension of children and adolescents.

The maximal rate of ouabain sensitive Na+ (pump), the maximal rate of Na+ and K+ furosemide (co-transport), the maximal rate of Na+ lithium countertransport and the rate constant of Na+ and K+ passive permeability were determined in the following population: 27 controls, 39 labile essential hypertensive, 10 stable hypertensive children, 6 normotensive offspring of hypertensive parent (s), and 19 hypertensive secondary to renal disease. The normal values for children were determined for all these various fluxes. When a rigid technique was applied and particularly when the post loading concentration of intracellular Na+ was determined and when the cells were not swollen by Na+ loading, the technique was reliable, reproducible and our results could be compared with the results found in adults by researchers using the same rigid technical criteria. In labile hypertension, 21% of adolescents had a decreased co-transport, 17% an increased countertransport and 6% an increased Na+ leak. In stable hypertension none had a decreased co-transport, 29% had an increased countertransport and 25% had an increased Na+ leak. Moreover, plasma norepinephrine was elevated in most of the patients presenting a decreased co-transport. Our results suggest that adolescents with labile essential hypertension and elevated plasma norepinephrine present with a decreased co-transport whereas adolescents with stable essential hypertension and normal or subnormal plasma norepinephrine present with an increased countertransport.