Effect of epoprostenol (prostacyclin, PGI2) on cerebral blood flow in man.

Cerebral blood flow has been measured using the non-invasive Xenon133 clearance technique in eight normal subjects during an infusion of epoprostenol (prostacyclin, PGI2) at a dose of 5 ng/kg/min. The results were compared with a control infusion of saline given in a balanced order. PGI2 was found to result in a reduction in cerebral blood flow of about 8%. PGI2 also caused a small drop in diastolic blood pressure and it is proposed that the fall in cerebral blood flow may have been the result of disturbed autoregulation. The findings suggest that the therapeutic use of PGI2 in patients with cerebral artery spasm would not be accompanied by undesirable intracerebral steal.