Effect of ischemic anoxia on electrical and mechanical activity of the totally isolated porcine stomach.

Electrical and mechanical activity were recorded from totally isolated whole porcine stomachs perfused with homologous blood. Stagnant, complete ischemia was then produced by closing the gastric artery and vein for various periods of time up to 3 h. After a given period of ischemia, blood was recirculated for 10 min and then pentagastrin was injected into the gastric artery. The vagus nerve was also electrically stimulated at various stages of anoxia and recirculation. After up to 90 min of ischemia, stomachs were able to demonstrate electrical control activity of low frequency after 10 min of blood recirculation. After injection of pentagastrin, electrical control activity rapidly became normal. When ischemia lasted 120 min or longer, recirculation of blood did not induce reappearance of electrical control activity, but pentagastrin injection produced a normal response. After ischemia of 240 min duration or longer, recirculation and pentagastrin had no effect. In previously ischemic stomachs the response to vagal stimulation occurred only in the stomachs responding to pentagastrin.