Effect of secretin on myoelectrical and mechanical activity of the isolated canine stomach perfused ex vivo.

Totally isolated whole canine stomachs, perfused ex vivo with homologous blood, were used for recording of myoelectrical and mechanical activity prior to and following the injection of secretin. Secretin was given as flash injections (0.5 - 32 U) or constant infusions (60 U/h). Background stimulation of stomachs was obtained by intragastric instillation of fluid, by the infusion of pentagastrin or bethanechol chloride, and by electrical stimulation of the Latarjet branch of the vagus nerve. Hormones were injected into the gastric arterial circulation. Secretin had no effect on the frequency of electrical control activity. Secretin inhibited electrical response activity when injected against the background of electrical vagus stimulation. Secretin also inhibited or decreased mechanical activity of the gastric antrum, recorded at the site of the antral strain gauge.