Effect of glucagon on myoelectrical and mechanical activity recorded from the isolated homologous perfused canine stomach

Totally isolated whole canine stomachs, perfused ex vivo with homologous blood, were used for recording of myoelectrical and mechanical activity. Hormones were administered into the arterial system of the isolated stomach. Pentagastrin, methacholine and electrical stimulation induced premature control potentials with uncoupling of the normal, phase locked, pattern of electrical control activity and also stimulated mechanical activity. Electrical response activity was also present. When the three modes of stimulation were applied during the infusion of glucagon, a marked inhibitory effect was observed. This effect consisted of inhibition of mechanical activity and of electrical response activity. Glucagon also decreased, but did not suppress the changes in electrical control activity observed after electrical stimulation and after injection of pentagastrin or methacholine into the gastric artery of the isolated stomach. During infusion of glucagon, the mean gastric arterial perfusion pressure and gastric peripheral vascular resistance were reduced.