The effects of prostacyclin on glycemia and insulin release in man

Abstract Prostacyclin /PGI 2 / administered intra-arterially or intravenously to patients with peripheral vascular disease exerted a hyperglycemic effect. In normoglycemic patients receiving PGI 2 at a dose of 5 ng/kg/min these effects were barely detectable, but they became unmasked by a rapid glucose injection. In diabetic patients the same PGI 2 dose led to distinct elevation in blood glucose. Prostacyclin at a dose of 10 ng/kg/min raised blood glucose levels both at rest and after stimulation with glucose, and opposed effectively hypoglycemic action of tolbutamide in non-diabetic patients. PGI 2 repressed glucose-induced insulin release in some normoglycemic patients but in others it either increased it or did not affect it. While hyperglycemic effects are reversible when PGI 2 infusion is stopped, and do not interfere with the usual therapeutic administration of prostacyclin for a few days they, nevertheless, might constitute a risk in a patient with poorly controlled diabetes.