A morphometric study of the effects of bile on the G cells of the antral mucosa of the dog

A new model for production of chronic gastric ulcer by duodenogastric reflux in rats

We have established an experimental model of chronic gastric ulcer, in rats which transection of the lower horizontal portion of the duodenum and anastomosis of the forestomach to the upper part of the jejunum caused regurgitation of all duodenal juice into the stomach. After 3, 6, 12, and 30 wk, all treated rats developed an ulcer in the prepyloric region on the lesser curvature of the stomach. More than half of the antrum was finally involved in the ulcer. Histologic studies revealed chronic ulcers quite similar to human ones. As a control series, transection at the pylorus failed to produce an ulcer. Although many papers have appeared regarding the experimental production of chronic gastric ulcer, most of the studies reported have applied chemicals, drugs, or mechanical injury to the gastric mucosa. Our model produced chronic regurgitation of duodenal juice as a natural phenomenon, and uniformly resulted in ulcer formation. Intragastric total bile acid concentrations were significantly elevated in the reflux group. Serum gastrin levels, the thickness of the fundic mucosa, and the height of fundic gland were also significantly increased. Thus, the detergent action of bile acids and the increased acid secretion were assumed to play an important role in ulcer formation. Further studies using this model are warranted on the pathogenesis of chronic peptic ulceration.

[Bile acid reflux following stomach surgery on rats (author's transl)]

Using rats in a standardized animal experiment, the extent of duodenogastric reflux was studied eight months postoperatively following SPV with and without pyloroplasty. The reflux was determined by enzymatically testing the concentration of bile acid secretion withdrawn from the stomach intraoperatively. Serving as comparison were laparotomies, simple pyloroplasties, and the obligatory reflux models: resection after BII without enteroanastomosis. After SPV with and without pyloroplasty, the extent of duodenogastric reflux was less than in the control group. Specimens with simple pyloroplasty displayed a significantly greater reflux. The BII group had fivefold higher reflux than the control group. Since pyloroplasty can be considered a drainage operation, there is no retention of food particles in the stomach of the rat following SPV--an occurrence expected after SPV without pyloroplasty. However, due to the retarded stomach motility, the thickened chyme tends to linger at the opening of the stomach, thus reducing the duodenogastric reflux. According to our investigations, an increased duodenogastric reflux following SPV with or without pyloroplasty does not induce changes in the mucosa of the stomach.

The antral gastrin-producing cells in duodenal ulcer patients. A density study before and during treatment with cimetidine

A density study of the antral gastrin-producing cells has been performed, before and after eight weeks of treatment with a histamine H2-receptor antagonist (cimetidine 1 g per day), in a series of 38 patients suffering from chronic duodenal ulcer. The treatment produced a significant increase in numerical density and a decrease in mean cell volume. The volume density of the cells was unchanged, suggesting that the elevated serum-gastrin during treatment may be the result of gastrin-cell hyperplasia, without change in the total gastrin-cell volume. The authors suggest that G-cell hyperplasia demonstrated during cimetidine treatment may be a factor of importance with regard to the rapid recurrence of many ulcers after discontinuation of the treatment.