The influence of pharmacological stimulation and blockade of adrenergic receptors on the mesenteric blood flow response to glucagon was studied in anesthetized dogs. Electromagnetic flowmeter was used for recording of the superior mesenteric artery flow. The vasodilatory effect of glucagon was not blocked by dichloroisoproterenol. Vasoconstriction produced by the alpha-adrenergic agonist phenylephrine (neo-synephrine) hydrochloride was abolished in the splanchnic vascular bed by glucagon whether the hormone was administered before or during the phenylephrine infusion. The vasodilatory effect of phenoxybenzamine hydrochloride (Dibenzyline) was potentiated by glucagon selectively in the mesenteric region. It is concluded that the vasodilatory effect of glucagon on the mesentric vascular bed does not seem to be mediated via alpha-receptor blockade nor via stimulation of beta-receptors.
Tibblin S, Kock NG, Schenk WG. Response of Mesenteric Blood Flow to GlucagonInfluence of Pharmacological Stimulation and Blockade of Adrenergic Receptors. Arch Surg. 1971;102(1):65-70. doi:10.1001/archsurg.1971.01350010067017