Hydrochloric acid production by isolated gastric mucosa

Abstract

Intact tied tubes of frog and toad gastric mucosa secreted acid and mucus in vitro aerobically, and also produced an equivalent amt. of alkali ([plus or minus] 1%), which was neutralized by CO2 and passed into the nutrient soln. as HCO3 ions. No evidence of HC1 secretion was obtained when sheets of sheep, frog or toad gastric mucosa were incubated in Warburg cups, although their respiration was enhanced by histam-ine. This is an agreement with the conception that HC1 secretion into the lumen of the stomach is linked with an equivalent bicarbonate secretion into the nutrient soln. The QHC1 of active mucosae was often higher than the (Qo2) or the respiratory QCO2, and in these cases external supplies of CO2 were needed for the neutralization of alkali. The uncatalyzed rate of CO2 uptake, to neutralize alkali within very active oxyntic cells, is too slow by a factor of the order of 100, and makes it probable that the necessary extra uptake can be readily produced by the carbonic anhydrase within oxyntic cells. An-aerobically the tissue secreted neither acid nor mucus. Evidence is presented which disproves the theories of HC1 elaboration of Bull & Gray (1945) and Conway et al (1945).