Platelets and hypertension.

Various physiological changes of platelets and the vascular smooth muscle cell are intimately related. For this reason, in addition to the number of features in common between platelets and vascular smooth muscle and the increased risk for thromboembolic complication in essential hypertension, the platelet was used as an experimental model for the investigation of calcium-dependent functional anomalies associated with hypertension. It is demonstrated, by a sequential analysis of receptor and postreceptor events, that platelets in hypertension exhibit (a) a greater adenylate cyclase-activation and c-AMP-accumulation response to PGE1, (b) an enhanced epinephrine-induced phosphorylation response, and (c) an increased shape change sensitivity to serotonin and epinephrine. The anomalies in these calcium-dependent processes are linked to elevated free calcium concentrations in platelets from hypertensive subjects.