[Platelet aggregation in severe and malignant forms of hypertension: effect of treatment with prostaglandin E2].

Platelet aggregation was studied in patients with high and stable arterial hypertension that was mostly associated with the malignant syndrome, and the effect of PGE2 introduced into the blood flow as repeated intravenous infusions on platelet activity was assessed. The addition of low-dose inductor produced the greatest changes in platelet aggregation following platelet exposure to different ADP doses in the patients, as compared to normal subjects. Stimulation with 0.1 mumol ADP produced a 7-fold increase in platelet aggregation in hypertensive patients, as compared to the controls. Repeated administration of 1.2-1.5 mg PGE2 normalizes cell sensitivity to ADP. Mean arterial BP dropped by 15-45 mm Hg during the infusions and remained low for several days afterwards.