Potassium in mecholyl-stimulated gastric secretion in the dog

Previous work indicated that K concentration ([K]) of gastric juice rises abruptly after histamine injection, concomitantly with acid efflux. Using Heidenhain and vagal pouch dogs, these experiments (26 in all) were repeated with mecholyl and histamine. The concentration-time curves for K were similar for both stimuli with early rise in [K], its late fall below preinjection level, and eventual recovery. The initial rise tended to be smaller and occurred less often with mecholyl. Its occurrence after histamine was also inconsistent. [K] was poorly correlated with both acidity and volume-rate. Time curves for K output likewise were similar with both stimuli, but correlation with acid output was high. Exogenous histamine is not essential to this K efflux, which may represent a basic process associated with glandular, neural, or muscular stimulation in general.