Acetylsalicyclic acid restores acute insulin response reduced by furosemide in man

Prostaglandin E (PGE) infusion in normal man inhibits the acute insulin response to glucose. In order to determine whether endogenously released PGE might also inhibit insulin secretion, glucose-stimulated insulin responses were investigated in normal volunteers after furosemide (40 mg i.v.), a stimulator of endogenous PGE synthesis. Acute insulin response to glucose (20 g i.v.) was significantly reduced by furosemide (response before furosemide: 36 +/- 5 muU/ml; after furosemide: 26 +/- 5 muU/ml, m +/- SE, mean change 3--10 min, N = 8, P less than 0.01), whereas glucose disappearance rates were not modified after furosemide. Infusion of lysine acetylsalicylate (LAS), an inhibitor of endogenous PGE synthesis, completely reversed the inhibitory effect of furosemide on insulin secretion and also augmented acute insulin response to glucose (response before furosemide + LAS: 41 +/- 6 muU/ml; during furosemide + LAS: 50 +/- 7 muU/ml, N = 10, P less than 0.02). This effect was associated with an increase in glucose disappearance rates (P less than 0.05). These findings demonstrate that (1) furosemide inhibits glucose-induced acute insulin responses and (2) LAS completely reverses the inhibitory effect of furosemide and also accelerates glucose disposal. It is suggested that furosemide acts via the release of endogenous PGEs, which are known to inhibit insulin responses in man.