Differences of Ca2+ regulation between fibroblasts from blacks and whites

To explore the underlying causes predisposing blacks to essential hypertension, we have studied 45Ca2+ washout and cytosolic free Ca2+ (Cai2+) in quiescent skin fibroblasts from normotensive blacks and whites. Under basal conditions, there were no racial differences in 45Ca2+ washout and Cai2+. However, when stimulated by human serum, fibroblasts from blacks exhibited a higher 45Ca2+ washout associated with higher levels of Cai2+ transients than fibroblasts from whites. We conclude that fibroblasts from blacks demonstrate increased responsiveness to agonists in serum. If the same trend exists in vascular smooth muscle cells, it may predispose blacks to essential hypertension.