FACTORS AFFECTING THE ELECTRICAL POTENTIAL OF THE GASTRIC MUCOSA

Abstract

A brief review of the pertinent literature concerning the electrical potential of the gastric mucosa was presented. Apparatus and procedures for obtaining continuous photographic records of gastric potentials and secretions were described. Limited results of expts. on a small number of human subjects, and detailed results pertaining to gastric potential and secretions in dogs were presented and discussed. These results disclosed that the resting voltage of the stomach ranges between 40 and 100 millivolts. The mu-cosal surface is negative with respect to the serosal surface. The voltage attains its maximum when the stomach is at rest and the animal quiescent. Interference or trauma to the stomach lowers the potential difference across the mucosa. Systemic disturbance to other parts of the body, as by painful stimulation, also lowers the voltage, as does adrenalin. These observations indicate that the voltage may be modified by the sympatho-adrenal system. Also, the stimulant drugs pilocarpine and histamine reduced the gastric potential. The decrease caused by these drugs, especially pilocarpine,was prolonged. The reduction of voltage caused by all drugs tested roughly parallelled the time course of their therapeutic effectiveness. The reduction of potential caused by pilocarpine and histamine was sometimes associated with increased gastric secretions and sometimes not. Secretory responses of the stomach to these drugs were unreliable, whereas the electrical responses almost invariably occurred. Possible explanations for the results observed were presented and discussed. Some remarks were made relating to the possible diagnostic value of the gastric potentials.