The Effects of Glucagon and Glucagon-(1-21)-peptide on Antroduodenal Motility in Healthy Volunteers

Abstract

Since it has been argued that the spasmolytic effect of glucagon is related to the first 21 N-terminal amino acid residues, and not to the complete molecule, we have compared the effects of glucagon-(1-21)-peptide (G-(1-21) and glucagon on human antroduodenal motility. Glucagon and G-(1-21) were given as bolus injections to 30 healthy volunteers equally allocated into five groups. Each subject received two doses; one was placebo, 0.25, 0.5, 1.0 or 2.0 mg of glucagon, the other was an equimolar doses of G-(1-21) (placebo, 0.175, 0.35, 0.70 or 1.4 mg of G-1-21). The first injection was given during phase II of a migrating motility complex (MMC), and the next during the following phase II. Contractile activity was recorded using an oral tube with one sidehole positioned in the antrum and two in the duodenum. We confirmed that glucagon decreases the number of contractions in the antrum and duodenum and that normal phase II activity was restored within 20-40 minutes proportionally to the amount of the drug given. G-(1-21) did not change antroduodenal motility nor did it affect the phase II pattern in any of the groups. Neither were any side effects encountered. G-(1-21) does not seem to be an alternative to glucagon and other spasmolytic drugs for obtaining relaxation of the antroduodenal area.