Monophasic and diphasic action potentials of the stomach.

T HERHYTHMICACTIVITY of thestomach is associated with action potentials which are similar to those of other visceral muscles, including the heart (I). In the work reported here, these potentials were further analyzed by recording monophasic potentials and by leading off separately from longitudinal and circular muscles. Also the action of some drugs was investigated. The fact that monophasic potentials can be recorded is significant in itself, because it confirms the assumption that the smooth muscle of the stomach is a single muscular unit. Because several recent investigators have questioned the unitary character of visceral smooth muscles, some of the arguments for this assumption will be discussed.