Maximal acid secretory response to histamine and its relation to parietal cell mass in the dog

¹ Fels Research Institute, Temple University School of Medicine, Philadelphia, Pennsylvania

Gastric secretion in response to graded doses of histamine was obtained from the whole stomach in five trained dogs, and the animals were sacrificed to determine the total number of parietal cells in the stomach. Histamine was administered by single s.c. injection (H_sc) and continuous i.v. infusion (H_iv). Maximal histamine response (MHR) was determined, and studies permitting the construction of dose-response curves were carried out in three of the five dogs. Dose-response curves for acidity and for acid output and volume during the entire duration of secretory response to H_sc were also established. The MHR was found to be a linear function of both the total number of parietal cells (P < .01) and the fundic mucosal volume (P < .05). The magnitude of the MHR and the PCM in the five dogs was within the respective ranges reported in man, but the mean MHR per billion cells (9.8 ± 0.44 mEq/30 min.) and the mean MHR per 100 cc fundic mucosal volume (58.2 ± 5.12 mEq/30 min.) were both about 30% less than the respective ratios in man.