THE EFFECT OF PILOCARPINE, MECHOLYL, ATROPINE AND ALCOHOL ON THE GASTRIC POTENTIAL AND THE SECRETION OF HYDROCHLORIC ACID

Abstract

Pilocarpine or mecholyl admn. in dogs under certain exptl. conditions results in a decrease of the potential difference across the stomach wall. This decrease is associated with the onset of secretion of HC1. After the initial decrease of the potential, the potential may show relatively little change while the secretory rate may increase considerably. Administration of atropine, after secretion has been initiated by pilocarpine or mecholyl, results in a decrease in the secretory rate to zero and a concomitant increase in the potential. Ethyl alcohol-saline solns., applied to the mucosa of the stomach for certain periods of time, did not under the conditions of the expts. result in the secretion of HC1. The potential, on the other hand, was lowered by this procedure. A good correlation was found between the secretory rate and potential following application of alcohol-saline solns. to the mucosa in histamine stimulated stomachs. A marked lowering of the potential was always associated with a marked lowering of the secretory rate. Expts. were performed in which the diffusion potentials between 0.16 N HC1 and 0.9% saline and between 0.16 N HC1 and alcohol-saline solns. were measured. The difference between these diffusion potentials was, in general, definitely less than the decrease in the gastric potential. It was concluded that the decrease in the gastric potential was primarily due, in those cases where the decrease was relatively marked, to the effect of the alcohol on the gastric mucosa and not to an increase in the diffusion potential between the gastric soln. and chamber fluid. The results of the present investigation are discussed in the light of previously published work. It is concluded that the results of the present work, taken together with those previously published, give under the conditions of the expts. a fairly comprehensive picture of the relationship between the rate of secretion of HCl and the potential.