Myoelectrical and mechanical activity of isolated canine stomach perfused in vitro with fluorocarbon. Role of glucose, phosphate, calcium and strontium in the perfusate.

Abstract

Myoelectrical and mechanical activities were recorded from whole isolated canine stomachs perfused, intravascularly, with fluorocarbon emulsion, oxygenated in vitro. The perfusate was composed of an oxygen carrier, fluorcarbon, emulsified with a surfactant added to a simulated physiological solution. Bipolar electrodes and a strain gauge were used for recordings. Stomachs perfused as above for 5 h displayed normal electrical and mechanical activities. 'Normal' meaning identical with those observed under in vivo conditions or during perfusion with homologous blood. Normal response to electrical stimulation of a vagus nerve branch or to intraarterial injection of methacholine or pentagastrin were also observed. These functions of smooth muscles were not altered when glucose-free or glucose-and phosphate-free perfusate were used. In calcium-free perfusate, electrical and mechanical activities were absent and no responses to stimulants used were recorded. When calcium was added to the perfusate, these functions were restored to normal. Strontium was found to be an adequate substitute for calcium in fluorocarbon perfusate. Gastric secretions were alkaline and contained fluorocarbon emulsion.