Effect of epinephrine and norepinephrine on immuno-reactive insulin secretion from isolated islets of Langerhans.

Earlier studies have demonstrated the inhibitory nature of epinephrine and norepinephrine on pancreatic insulin release. The present study reports their effect on beta-cell IRI release in an isolated islet system. Results show that epinephrine and norepinephrine inhibit islet-IRI release at the 100-10 microM level. The alpha adrenergic blocker phentolamine (100 microM) but not the beta adrenergic blocker propranolol (100 microM) can reverse this catecholamine induced inhibition of islet-IRI release. This clearly suggests that epinephrine and norepinephrine inhibit insulin release via alpha-adrenergic pathway.