THE QUESTION OF A GASTRIC HORMONE

¹ The Department of Physiology, Edinburgh University

1. Edkins' observations regarding pyloric extracts and their effect in causing gastric secretion is confirmed. Extracts made from the cardiac and duodenal mucous membranes are less active; fundus extracts are comparatively inert, while jejunal and ileal extracts are ineffective.

2. Histamine causes gastric secretion when injected intravenously; contrary to the observations of Popielski and others, who only obtained secretion when it was injected subcutaneously or intramuscularly.

3. Adrenalin does not inhibit the secretion provoked by the above substances but may delay its outflow from the stomach. Adrenalin excites secretion in some individuals.

4. The distribution of the gastric excitant or gastrin in the stomach and duodenum corresponds with the distribution of mucoid glands ; it is suggested that the excitant is extracted from mucoid cells.

5. The blood of fed animals has no effect on gastric secretion when transfused directly or indirectly. The blood was taken at various intervals after a meal, and when citrated was injected either intravenously or eintraarterially into the recipient.

Since there is no gastric exciting substance in the blood after meals, it is concluded that the excitant found in pyloric and other extracts is not secreted into the blood stream and the mechanism of secretagogue action is not due to internal secretion.