Inhibition of Insulin Release by Norepinephrine in Man

Normal subjects were given glucose (300 mg/ min) or tolbutamide (1 g, intravenously), alone and during intravenous infusions of norepi-nephrine (6 lg/ min). Immunoreactive insulin concentration was less than expected during the infusions of norepinephrine, but returned to higher values after the norepinephrine infusions. From these data it is concluded that norepinephrine inhibits the release of insulin from pancreatic beta cells.