抄録
Presence of a substance inhibiting gastric secretion in salivary glands, which may be considered as the secretory source of sialogastrone (the substance in the saliva, inhibiting gastric secretion) was studied in comparison with other organs. Submaxillary glands and other organs of mice, rats, rabbits, and dogs were used as material and their aqueous extract was assayed for the gastric secretion inhibiting activity. Simultaneously, the difference from pyrogenic substance, which also exhibits similar gastric secretion inhibiting activity, was clarified. First, the gastric secretion inhibitory activity (G) and pyrogenic activity (P) of the pyrogenic substance (X-3) extracted from the saliva were assayed and the ratio G/P of the antisecretory activity to pyrogenic activity was calculated. The result of the assay showed that the ratio did not change in the presence of an inert protein. Therefore, the specificity of antisecretory activity of the extract fractions was judgeb from the ratio of G/P. Aqueous extracts from various organs were fractionated by gel filtrations on Sephadex G-100. The antisecretory activities of the total 253 fractions so obtained were assayed. The specific activity was found only in two fractions obtained from the submaxillary glands of mice, although the activity was also found in six fractions obtained from the stomach, pancreas, kidney, and spleen of mice and rats. However, the latter fractions could not be judged as the specific activity from the ratio of G/P, because of not being distinguishable from the antisecretory activity of mixed pyrogenic substances, and all the remaining fractions did not exhibit any antisecretory activity or did exhibit enhanced pyrogenic activity.
