Effects of alpha-adrenoceptor agonists and antagonists on insulin secretion, calcium uptake, and rubidium efflux in mouse pancreatic islets.

摘要: Epinephrine, norepinephrine or the more selective alpha-2 adrenoceptor agonist, clonidine, inhibited insulin release from isolated pancreatic islets of lean mice obese homozygous for gene ob. Clonidine was highly effective at 0.1 mumol/l. In contrast, preferential alpha-1 phenylephrine, had no only a modest effect 10 The effects clonidine were counteracted by yohimbine, blocker receptors, but not prazosine, an receptor blocker. glucose-stimulated uptake 45Ca2+ in consistently epinephrine. This yohimbine. on 86Rb+ preloaded islets. It is concluded that secretion suppressed agonism beta-cells and this mediated mechanisms other than transmembrane fluxes calcium potassium ions.