Adrenergic modulation of gastric inhibitory polypeptide secretion in man

Abstract

In order to examine the effect of adrenergic influences on gastric inhibitory polypeptide (GIP) secretion, a series of glucose tolerance tests was carried out in seven healthy volunteers during intravenous infusion of epinephrine (6 μg/min), epinephrine plus phentolamine (5 mg stat+0.5 mg/min), epinephrine plus propranolol (5 mg stat+0.08 mg/min), and saline. No drug infusion modified fasting GIP levels. Alpha-adrenergic stimulation (epinephrine+propranolol) significantly reduced the GIP response (PP<0.005) to oral glucose, compared with control experiments. Epinephrine alone and epinephrine+phentolamine did not influence glucose-stimulated GIP. These results suggest the possibility that the adrenergic nervous system may have a role in the regulation of GIP secretion in man.