1. Alterations in intracellular calcium have been implicated in the pathogenesis of essential hypertension. To see whether this is a generalized phenomenon we assessed cytosolic free calcium and intracellular calcium stores in neutrophils from normo- and hyper-tensive subjects, by trapping the fluorescent calcium indicator quin2 in intact cells.
2. Ten patients with untreated essential hypertension were compared with 10 age- and sex-matched normotensive subjects. The levels of cytosolic free calcium and intracellular calcium stores releasable by the calcium ionophore ionomycin did not differ. No significant relationship was found between blood pressure and the calcium parameters in all 20 subjects studied.
3. The results indicate that essential hypertension is not associated with a membrane defect in calcium handling of all human cell systems, leading to generalized increases in resting values of cytosolic free calcium.
4. Neutrophils do not appear to be a good model for intracellular calcium handling in vascular smooth muscle.