The relationship between oxygen consumption and acid secretion was studied in 28 totally isolated ex vivo canine stomachs, perfused extracorporeally with homologous blood. Two hundred six 30-min samples of gastric juice and blood were collected for biochemical analysis. Paired values of HCl (microequivalents per minute) and O2 consumption (micromoles per minute) were then analyzed by the method of least squares, using a computer. Linear correlation was calculated between these two values. The correlation coefficient was 0.9518 and the slope of the line was 0.512. The ratio of hydrogen ions produced to oxygen molecules consumed was 1.18 ± 0.53. The range of titratable H+ found in this study was from 0 to 833 μequiv/min and the range of O2 consumed was from 18 to 442 μmol/min.

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Principal glycoproteins and amino acids were determined in porcine gastric juice obtained from totally isolated stomachs perfused extracorporeally with homologous blood. Acid juices collected during prolonged stimulation of stomachs with histamine or pentagastrin, infused into gastric arteries, were used. All samples showed the presence of galactose, glucosamine, galactosamine, fucose, mannose and sulphate. Galactose and glucosamine were found in equimolar amounts and the galactose to galactosamine ratio was, in most samples, 2:1. Compared with human non-stimulated gastric juice studied by others, marked differences were found in the relationship between carbohydrate components and between amino acids. Porcine gastric juice contained much more protein than human gastric juice. Some characteristics of porcine mucinous secretion may be due to conditions of juice collection from the isolated gastric preparation.

Isolated, ex vivo perfused, canine stomachs were used for this study. Gastric secretion, myoelectrical activity and mechanical activity were recorded during stimulation of gastric function with pentagastrin or histamine alone or combined with calcium gluconate. Secretagogues and calcium were infused into the gastric arterial circulation. Hypercalcemia induced significant inhibition of pentagastrin, stimulated gastric secretion, but did not affect the secretion stimulated by histamine. Hypercalcemia also induced an increase of frequency of cycles of electrical control activity and a decrease of mechanical activity of the gastric antrum. The effect of hypercalcemia on gastric motor function was similar in the nonstimulated stomach and during the infusion of secretagogues used in this experiment.

Electrical and mechanical activity was recorded from totally isolated porcine stomachs perfused with homologous blood. The electrical control activity, response activity, and mechanical reaction to various hormones and drugs stimulating these activities were recorded. The drugs were injected directly into the gastric artery of the isolated organ. Normal response to cholinergic stimulants and to pentagastrin was observed. The effect of blockers such as atropine, hexamethonium and tetrodotoxin on the action of stimulants was also assessed. The results of this study suggest that the release of acetylcholine is involved in the mechanism of action of pentagastrin. They also demonstrate the usefulness of the isolated porcine stomach approach to the study of gastric myoelectrical and mechanical activity.