Regulation of insulin secretion by cAMP in rat islets of Langerhans permeabilised by high-voltage discharge.
Adenosine 3',5-cyclic monophosphate (cAMP) was shown to stimulate insulin secretion from electrically permeabilised islets of Langerhans incubated in Ca2+/EGTA buffers. cAMP-induced insulin secretion occurred in the presence of either sub-stimulatory (50 nM) or stimulatory (greater than 100 nM) concentrations of Ca2+. Similar effects on secretion were obtained in response to 8-bromo-cAMP (8-Br-cAMP) or the phosphodiesterase inhibitor, 3-isobutyl-1-methylxanthine. Forskolin (0.2-20 microM) increased adenylate cyclase activity and enhanced insulin secretion from the permeabilised islets. These results suggest that, in electrically permeabilised islets, cAMP-induced insulin secretion is not dependent on changes in cytosolic Ca2+.
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002463:Cell Membrane Permeability; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology*; D004558:Electric Stimulation; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D013268:Stimulation, Chemical
D007328:Insulin; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D015056:1-Methyl-3-isobutylxanthine