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Biomedical subjects

L Olbe

Publications and source records attributed to L Olbe.

At least 163 records · Page 9Linked to original sources
PubMed1977

Is there an oxyntopyloric reflex for release of gastrin in man?

Plasma gastrin concentrations and gastric acid output were measured during graded balloon distention of the gastric fundus and body in 20 patients with duodenal ulcer. Acid output rose stepwise with increasing distention volumes but plasma gastrin remained unchanged. During intragastric neutralization in 5 of these subjects, fundic distention did not elicit a significant rise in plasma gastrin, whereas the acid response was similar to that observed in the control study when the gastric contents were acid. In 8 of the 20 patients, proximal gastric vagotomy profoundly suppressed the acid response to fundic distention. Basal plasma gastrin concentrations were elevated after vagotomy but were unchanged during graded fundic distention. The results suggest that neural reflex activation of the oxyntic glands is the main mechanism by which fundic distention stimulates acid secretion in man. The failure of fundic distention to release gastrin does not, however, completely rule out the existence of an oxyntopyloric distention reflex for gastrin release in man. Fundic distention in man seems to both stimulate acid secretion and induce an inhibitory mechanism acting on acid secretion. This inhibitory mechanism may, purely speculatively, also mask the effect of an oxyntopyloric reflex for gastrin release. The present study and earlier work suggest that in man distention of the stomach is a poor stimulus for release of gastrin, regardless of whether the pyloric or the oxyntic gland area, or both, are distended.

Adult↗
PubMed1976

Gastric acid responses to graded i.v. infusion of pentagastrin and histalog in peptic ulcer patients before and after antrum-bulb resection.

Gastric acid responses to graded i.v. infusion of pentagastrin and Histalog were determined in peptic ulcer patients. Single-day multiple-dose tests were performed. The sensitivity to the humoral stimuli as determined by the calculated ED50's was not significantly different for duodenal ulcer patients with moderate (DUmod) or massive (DUmass) observed hypersecretion or for gastric ulcer (GU) patients: median ED50's of pentagastrin were 6.2, 6.6, and 13.1 mug/h in 18 DUmod, 22 DUmass and 7 GU patients respectively, and median ED50's of Histalog were 16.6, 25.3, and 17.1 mg/h in 14 DUmod, 10 DUmass and 6 GU patients respectively. Antrum-bulb resection significantly reduced basal acid secretion and maximal acid responses to the humoral stimuli (about 45% reduction) but did not significantly change the loss of gastric contents to the intestine or the sensitivity to the humoral stimuli (median ED50 of pentagastrin increased from 5.2 to 6.7 mug/h in 14 patients, and median ED50 of Histalog increased from 16.0 to 20.8 mg/h in 12 patients), suggesting that the intact antrum-bulb region of the ulcer patient is controlling the capacity to secrete acid, and indicating that antrum-bulb gastrin is an important trophic factor for the parietal cells in man.

Betazole↗
PubMed1976

The effect of long-term postoperative pentagastrin infusion on the maximal acid responses to pentagastrin in patients subjected to antrectomy.

Six duodenal ulcer patients subjected to antrectomy were given a continuous i.v. infusion of pentagastrin in a dose just below ED50 during 1 week in the immediate postoperative course. The peak acid output following stimulation with pentagastrin (PAOG) was determined preoperatively and 1 and 5 weeks postoperatively. PAOG was determined preoperatively and 1 week after antrectomy in a control group of 25 duodenal ulcer patients, and preoperatively and 5 weeks after antrectomy in another control group of 19 duodenal ulcer patients. One week post-antrectomy the PAOG was significantly less reduced (23%) in the pentagastrin infusion group than in the control group (46%). The reductions of PAOG 5 weeks post-antrectomy were not significantly different in the pentagastrin infusion group and the control group. The results show that the dysfunction of the parietal cells, reflected in a decreased capacity to secrete acid following antrectomy, can be partly reversed by continuous administration of pentagastrin in the immediate postoperative course. The results are interpreted as suggesting that antral gastrin in man, besides its property to stimulate acid secretion, also has a trophic effect on the parietal cells in analogy with the postulated trophic effect of antral gastrin in rats.

Adult↗
PubMed1976

The effect of antral distension on acid secretion and plasma gastrin in duodenal ulcer patients.

The effect of antral balloon distension on acid secretion and the plasma gastrin concentration was studied in 8 duodenal ulcer patients. Antral distension significantly increased the acid secretion to about 30% of the peak acid response to pentagastrin without any change in the plasma gastrin concentration. Antral distension and concomitant intragastric neutralization, with the intention of facilitating release of antral gastrin, produced about the same acid response and did not evoke any plasma gastrin increment. The results suggest that the acid response to antral distension in duodenal ulcer patients is evoked without contribution of the gastrin mechanism, and that the acid response is probably mediated via a pyloro-oxyntic reflex. In this respect the duodenal ulcer patient seems to differ from the healthy subject, in whom antral distension produces no acid response, and from the dog, in which release of gastrin as well as pyloro-oxyntic reflex participate in the acid response to antral distension.

Adult↗
PubMed1975

The effect of intragastric neutralization on the gastric acid response to antral distension in man.

The gastric acid secretion in response to graded antral distension was determined in healthy subjects and in peptic ulcer patients with water perfusion or alkaline buffer perfusion of the stomach, giving an intragastric pH of 1.8-3.0 and 6.2-8.3 respectively. Intragastric neutralization increased the basal acid secretion in healthy subjects and gastric ulcer patients but did not change the basal acid secretion in duodenal ulcer patients. Distension of the antrum produced the same secretory effect with and without intragastric neutralization: no increased acid response in healthy subjects, a slight acid response in patients with a quiescent duodenal ulcer or a gastric ulcer, and a more pronounced acid response in patients with an active ulcer, amounting to about 30% of the peak acid response to pentagastrin. The results show that: a) the peptic ulcer patients - and particularly patients with an active duodenal ulcer - are more sensitive to the acid secretory effect of antral distension than healthy subjects; b) increasing the intragastric pH above 20 does not enhance the acid response to antral distension; c) the acid secretory effect of antral distension is markedly less in man than the effect observed in the dog.

Adult↗
PubMed1975

Gastric acid response to antrum distension in man.

Gastric acid secretion under basal conditions and in response to graded balloon distension (50 ml, 100 ml, 150 ml) of the antrum was determined in healthy subjects and in peptic ulcer patients. In patients with a quiescent duodenal ulcer or a gastric ulcer antrum distension produced slight acid responses. The acid response to antrum distension was of quantitative importance only in patients with an active duodenal ulcer, amounting to 35 percent of the maximal acid response to pentagastrin. The healthy subjects did not respond with acid secretion to antrum distension. The pH of the gastric contents in the present series was 1.8-3.0, being lowest in patients with an active duodenal ulcer. Thus, the acid secretory effect of mechanical stimulation of the antrum seems qualitatively different in healthy subjects and ulcer patients, with a marked acid response in patients with an active duodenal ulcer.

Adult↗