Decreased 45calcium uptake in red cells of patients with essential hypertension.

Decreased 45calcium uptake was observed in red cells of 20 patients with essential hypertension. Equilibration of extracellular 45calcium with intracellular calcium was not achieved within 60 min in red cells of either hypertensive patients or control subjects. By introducing the ionophore A23187, equilibrium conditions were attained for red cells of both categories of individuals. Still the discrepancy in 45calcium uptake was preserved between them. These results support the view that red cells of hypertensive patients have an altered membrane permeability to calcium, possibly reflecting also a greater exchangeable pool of cytosolic free calcium.