Cyclic  nucleotides in pancreatic islets. Tolbutamide- and arginine-induced insulin release.
With the use of isolated rat islet perfusion, levels of the islet cyclic adenosine 3' ,5' -monophosphate (cAMP) were compared with dynamic insulin secretion induced by tolbutamide and arginine. Tolbutamide elevated islet cAMP rapidly and augmented both glucose-induced islet cAMP levels and insulin secretion; arginine, however, did not elevate islet cAMP but did enhance glucose-induced insulin secretion. Since the latter result could have been modulated by cyclic guanosine 3' ,5' -monophosphate, this cyclic nucleotide was also measured and found to remain unchanged during stimulation of insulin secretion by arginine and a combination or arginine and glucose. Thus, the action of tolbutamide appears to  be modulated in part by cAMP, whereas arginine appears to augment insulin secretion independently of cyclic nucleotides.
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D000242:Cyclic AMP / Q000032:analysis*; D005947:Glucose / Q000494:pharmacology; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000032:analysis / Q000187:drug effects*; D051381:Rats; D014044:Tolbutamide / Q000494:pharmacology*
D007328:Insulin; D001120:Arginine; D014044:Tolbutamide; D000242:Cyclic AMP; D005947:Glucose