A SPECIFIC BETA(3)-ADRENOCEPTOR AGONIST INDUCES INCREASED PANCREATIC-ISLET BLOOD-FLOW AND INSULIN-SECRETION IN RATS

In order to study the role of beta(3)-adrenoceptor stimulation on insu lin secretion in mts, plasma insulin level and islet blood flow were m easured during treatment with CL 316243 which is chemically named diso dium (R, ]amino]propyl]-1,3-benzodioxole-2,2-dicarboxylate, a specific beta(3)-adrenoceptor agonist. CL 316243 induced a marked increase in both islet blood flow and plasma insulin concentration without changes in whole pancreatic blood flow. This increase was totally prevented w hen the rats were pretreated with bupranolol, a beta(1),beta(2),beta(3 )-adrenoceptor antagonist, but not with nadolol, a beta(1),beta(2)-adr enoceptor antagonist. We conclude that beta(3)-adrenoceptor stimulatio n provokes a marked vasodilatation of microvessels in the islets of La ngerhans, which in turn could contribute to the increase in insulin se cretion.