[Effects of 6-oxo-PGE1 on the renin-angiotensin-aldosterone system, blood pressure and platelet aggregability in man].

6-oxo-prostaglandin E1 (6-oxo-PGE1), has recently been postulated as being a possible metabolite of PGI2 and/or 6-oxo-PGF1 alpha. This compound possesses a vasodilatory, renin secretion activity and platelet aggregation inhibiting activity in the dog and rat and is more stable than PGI2. But the systemic effects of 6-oxo-PGE1 on man is not known. The present study was designed, therefore, to determine the effects of 6-oxo-PGE1 on blood pressure (BP), the renin-angiotensin-aldosterone system and platelet aggregability in man. 6 healthy male volunteers (mean age: 24.3 +/- 1.2 years) and one patient with Shy-Drager syndrome (a 57 year old female) were studied. 6-oxo-PGE1, dissolved in physiological saline, was infused intravenously at three different doses of 7.5, 15 and 30 ng/kg/min, for 15 min each. Blood samples were collected every 15 minutes for measurements of plasma renin activity (PRA), plasma aldosterone (PA), plasma cortisol (PC) and platelet aggregation inhibiting activity (Agg-inhibition). BP and pulse rate (PR) were recorded every 2 minutes. PRA, PA and PC did not change during or after the infusion. However, the platelet aggregation was significantly (p less than 0.05) inhibited in a dose-dependent manner, and this was still observed at 30 minutes after the termination of the infusion. Neither systolic or diastolic BP changed during the infusion but rose after the termination of the infusion.(ABSTRACT TRUNCATED AT 250 WORDS)