THE ACTION POTENTIALS OF THE STOMACH

Abstract

The action potentials of the exposed stomach of the dog, cat and guinea pig were recorded using a new type of differential calomel electrode of very small dimensions. In the dog the differential potential accompanying each wave of contraction agrees with that of the heart, except for the longer duration of the complex. The waves of the curve, therefore, were designated as R, S and T waves. A single electric shock can produce a premature contraction followed by a prolonged pause similar to the response of the heart. The monophasic potential was derived from the differential potential by graphic integration. In the dog it shows chiefly a period of sustained negativity, as in cardiac muscle, but, in the cat and guinea pig, spikes are superimposed on the sustained potential. It is shown that the potentials from visceral muscles cannot be explained if the muscle fibers are considered as being independent units. The striking similarity of the activity of the stomach with that of the heart as well as other observations can be explained on the assumption that conduction is due to a syncytial arrangement of the muscle fibers.