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Biomedical subjects

J de Graef

Publications and source records attributed to J de Graef.

17 recordsLinked to original sources
PubMed1984

Roles of gastrin release and neural reflexes during the gastric phase of acid secretion in dogs.

The acid secretion from the main stomachs and from denervated Heidenhain pouches in response to peptone meals infused in the stomach was determined in 4 dogs. When expressed as percent of the maximal acid response to histamine, the acid secretion from the innervated and from the denervated fundic mucosa was similar, but the response from the Heidenhain pouch was larger when expressed as percent of the maximal response to pentagastrin. These studies indicate that, under the conditions used, short (gastrogastric) and long (vagovagal) reflexes during the gastric phase, are of minor importance in inducing the acid response to the meal.

Animals↗
PubMed1984

[Interactions between secretin and somatostatin on acid secretion and gastric emptying in dogs].

Secretin and somatostatin are two peptides released by H+ ions. The fact that blood levels of these peptides increase during the postprandial period makes them the most probable candidates for gastric acid secretion retrocontrol . The aim of our study was to determine whether a potentiation of inhibitory effects exists when the two peptides are administered simultaneously. Seven dogs were provided with a gastric fistula. Gastric acid secretion was stimulated by intragastric infusion of a bactopeptone solution or by pentagastrin (1 microgram X kg-1 X h-1). Acid outputs and gastric emptying rates were measured at regular intervals. The tests were repeated during intravenous infusion of secretin (0.125 micrograms X kg-1 X h-1), somatostatin (0.2 micrograms X kg-1 X h-1) or both peptides together at the same doses. Both secretin and somatostatin inhibited acid secretion and gastric emptying. The inhibition was not greater when both peptides were administered together. Under the conditions used, no potentiation or additive effects between the two peptides were observed on gastric acid secretion or gastric emptying.

Animals↗
PubMed1978

Antral gastrin cell proliferation after vagotomy in rats.

The total number of antral gastrin cells, the antral surface area and the serum gastrin concentration were determined in two groups of rats. The animals had been submitted at random either to vagotomy and pyloroplasty or to pyloroplasty alone 3 weeks before. The indirect immunoperoxidase reaction and a direct quantitative histological method were used to count the gastrin cells. Radioimmunoassay was used to estimate the serum gastrin concentration. The total number of gastrin cells in the stomach was 52% (p less than 0.01) more elevated in the vagotomized animals. Both antral mucosal surface and calculated concentration of gastrin cells per square millimeter of mucosa were significantly higher (0.01 less than p less than 0.05) in this group of animals. The serum gastrin values were significantly (p less than 0.01) more elevated after vagotomy. These observations indicate that vagotomy may induce an antral gastrin cell hyperplasia which could explain in part the hypergastrinemia observed after this surgical procedure.

Animals↗
PubMed1976

Effect of jejunal resection on the gastric acid secretory response to pentagastrin, histamine and feeding in dogs.

In dogs with gastric fistulas and denervated pouches from the oxyntic area, the acid secretory responses to a meal and to graded doses of histamine and pentagastrin were measured before and after resection of the upper half of the small bowel. Intestinal resection caused a small but significant increase in submaximal and maximal response from the pouch to histamine and pentagastrin without modification of the ED50. This effect was not observed in the innervated stomach. The response from the pouch to feeding was markedly increased and prolonged. These data indicate that both an increase in stimulation and an increase of the response to this stimulation are responsible for the increased acid secretion observed in the pouch when resected dogs were fed. These effects could be explained by the withdrawal of inhibitors of intestinal origin.

Animals↗
PubMed1976

Effect of feeding on catabolism and activity of exogenous gastrin in dogs.

The effect of meal upon the catabolism and activity of exogenous gastrin was tested in 4 antrectomized and 4 non antrectomized dogs with Heidenhain pouches. In both antrectomized and non antrectomized dogs infused with exogenous gastrin, the meal decreased the serum gastrin level. This decrease amounted to about 20%, 60 minutes after feeding and the gastrinemia then returned gradually to control levels. In non antrectomized dogs, infusion of a near maximal dose of gastrin increased the acid response to the meal to a level above the maximal histamine acid output. Exogenous gastrin also increased the acid response to a meal in antrectomized dogs. These data indicate: 1) That feeding increases the metabolic clearance rate of exogenous gastrin. This effect could be at least partly related to changes in the intestinal blood flow. 2) That, after feeding, one or several hormones capable of stimulating the acid secretion but unrelated to gastrin are probably released. These hormones could be of major importance in the response of denervated pouches to feeding.

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