Theophylline prevents the inhibitory effect of prostaglandin E2 on glucose-induced insulin secretion in man.
This study was undertaken to assess the mechanism by which prostaglandins of the E series inhibit glucose-induced insulin secretion in man. Acute insulin response (mean change 3-10 min) to iv glucose (0.33 g/kg) was decreased by 40% during the infusion of prostaglandin E2 (10 micrograms/min) and glucose disappearance rates were reduced (P less than 0.05). Insulin response to arginine (5 g iv) and tolbutamide (1 g iv) were not affected by the same rate of prostaglandin E2 infusion. The inhibitory effect of prostaglandin E2 on glucose-induced insulin secretion was prevented by theophylline (100 mg as a loading dose followed by a 5 mg/min infusion), a drug that increases the intracellular cAMP concentrations by inhibiting phosphodiesterase activity. Our data suggest the involvement of the adenylate cyclase system in the inhibitory action of prostaglandin E2 on glucose-induced insulin secretion in man.
Giugliano
D
D
Cattedra di Diabetologia e Dietoterapia, I Facoltà di Medicina, Università di Napoli, Italia.
Cozzolino
D
D
Salvatore
T
T
Giunta
R
R
Torella
R
R
D000328:Adult; D001120:Arginine / Q000494:pharmacology; D001786:Blood Glucose / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D015232:Dinoprostone; D005260:Female; D005947:Glucose / Q000008:administration & dosage*; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male; D011458:Prostaglandins E / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D013806:Theophylline / Q000494:pharmacology*; D014044:Tolbutamide / Q000494:pharmacology
D001786:Blood Glucose; D007328:Insulin; D011458:Prostaglandins E; D001120:Arginine; D014044:Tolbutamide; D013806:Theophylline; D000242:Cyclic AMP; D005947:Glucose; D015232:Dinoprostone