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Biomedical subjects

L Olbe

Publications and source records attributed to L Olbe.

At least 145 records · Page 8Linked to original sources
PubMed1979

Cephalic phase of pancreatic-polypeptide secretion studied by sham feeding in man.

The effect of sham feeding on pancreatic-polypeptide (PP) secretion was studied in 26 duodenal ulcer (DU) patients and in 8 healthy subjects. Modified sham feeding (MSF) by the 'chew and spit' technique induced a rapid increase in plasma concentrations of PP both in DU patients, 56 (2-138) pmol/l, and in the healthy subjects, 24 (2-45) pmol/l, median peak-increment and range. Four out of 26 DU patients and 2 out of 8 healthy subjects did not show any PP response to MSF. The PP response to MSF was abolished by pretreatment with atropine, or benzilonium, a quarternary anti-muscarinic agent with minimal cerebral actions. The PP response to MSF was not dependent on the gastric acid response, since a PP response to sham feeding was found in 13 out of 17 patients with selectively denervated parietal cell area, and thus, without acid response. During adequate sham feeding, in which the food is also swallowed but does not reach the stomach, the PP increment, 100 (81-129) pmol/l, was larger than during MSF in the same patients, 51 (8-78) pmol/l, median and total range, P less than 0.05, N = 7. No correlation was found between the PP and acid responses to sham feeding. It is concluded that cephalic stimulation provoked by tasting, chewing and swallowing is a major stimulus in the initial, rapid PP response during a meal; and that the PP cells are probably stimulated directly by a cholinergic mechanism.

Adult↗
PubMed1979

Gastric bile acids before and after Roux-en-Y transposition for bile reflux gastritis and in asymptomatic controls.

Eight patients with severe postgastrectomy syndromes for predominantly bile reflux gastritis were examined by quantification of bile acids in the gastric remnant before and after a standardized liquid meal. Gastroscopy with biopsy and determination of gastric acid secretion and gastric emptying were performed. Six of the patients were also studied 3 months after Roux-en-Y transposition. Controls consisted of six completely asymptomatic partially gastrectomized patients studied 4--11 years postoperatively and six healthy students without any history of gastrointestinal disease. The healthy subjects had virtually no reflux of bile acids in the fasting state or after a meal. Both the symptomatic and asymptomatic patients had reflux in the fasting state and postprandially. The reflux of bile acids was, however, significantly greater late in the fasting period and early in the postprandial period in the symptomatic patients than in those without symptoms. The Roux-en-Y transposition eliminated the bile acid reflux and the symptoms of bile reflux gastritis but did not change the gastric emptying pattern. In patients with reflux gastritis the acid disappearance in the gastric remnant was moderate and the maximal acid output was unchanged after Roux-en-Y transposition.

Aged↗
PubMed1979

Synchronous oscillations in the basal secretion of pancreatic-polypeptide and gastric acid. Depression by cholinergic blockade of pancreatic-polypeptide concentrations in plasma.

The effect of cholinergic blockade on the concentrations of pancreatic-polypeptide (PP) in plasma was studied in 19 patients with duodenal ulcer (DU) and 16 control subjects. PP concentrations increased with age both in control subjects and in DU patients. In the DU patients atropine or benzilonium, an antimuscarinic agent with minimal cerebral actions, reduced PP concentrations from 47 (8-220) to 28 (7-53) pmol/liter, n = 18, median and total range. In the control subjects atropine suppressed the PP concentrations from 17 (0-257) to 11 (0-41) pmol/liter, n = 15. Cholinergic blockade had only a minor effect in 1 patient and 1 control, both with high PP concentrations. Both in the DU patients and in the control group the suppression by the cholinergic blockade was most marked in subjects with elevated PP concentrations. Spontaneous acid and PP secretion were measured simultaneously in 25 DU patients. No correlation was found between median acid secretion and median concentrations of PP. However, in the individual patient a positive covariation was found between fluctuations in spontaneous acid secretion and fluctuations in PP concentration. P less than 0.005. We conclude that plasma concentrations of PP in the basal state are suppressible by cholinergic blockade and that PP concentrations fluctuate synchronously with the spontaneous secretion of gastric acid. These results suggest that PP concentrations in plasma before and after cholinergic blockade may possibly serve as indicator of abdominal vagal tone.

Adult↗
PubMed1978

Nervous release of vasoactive intestinal polypeptide in the gastrointestinal tract of cats: possible physiological implications.

1. The release of vasoactive intestinal polypeptide (VIP) into blood from the gastrointestinal tract was studied when eliciting autonomic nervous effects known to be mediated via non-adrenergic, non-cholinergic nerve fibres. All studies were performed on animals given atropine. 2. Electrical stimulation of the low threshold vagal fibres to the stomach did not significantly change gastric volume or VIP concentration in the venous effluent from the stomach. Stimulating the high threshold fibres, on the other hand, produced a gastric relaxation concomitant with a significant increase of venous plasma VIP concentrations. When eliciting a similar vagal relaxation of the stomach by distending a balloon the oesophagus a significant increase of venous plasma VIP concentration was also recorded. 3. Mechanical stimulation of the mucosa of the small bowel increased intestinal blood flow and a significant increase of venous plasma VIP concentration was observed. 4. Stimulation of the pelvic nerves to the colon produced a transient vasodilation and a significant increase of VIP in the venous effluent from the large bowel. A maintained vasodilation in the colon was induced by mechanically stimulating the rectal mucosa. This vascular response was accompanied by a significant raise of venous plasma VIP concentration. 5. The results demonstrate that all the studied nervous effects known to be mediated via non-adrenergic, non-cholinergic nerve fibres were accompanied by significant increases of the VIP concentration in the venous effluent. The possible physiological implications of these findings are discussed and it is proposed that VIP may be a neurotransmitter in the gastrointestinal tract.

Adrenergic Fibers↗
PubMed1978

Inhibitory effect of cimetidine on gastric acid secretion vagally activated by physiological means in duodenal ulcer patients.

Vagal activation of gastric acid secretion by modified sham feeding in six patients with duodenal ulcer produced a peak acid response amounting to 52% of the peak acid output after pentagastrin stimulation (PAOpg). Cholinergic reflex stimulation of gastric acid secretion by fundic distension in another six patients with duodenal ulcer produced a peak acid response of 45% of PAOpg. Intravenous infusion of cimetidine in a dose of 100 mg/h markedly inhibited the acid sham feeding response by 90-100% and almost abolished the acid response to fundic distension. The results suggest that gastric acid secretion evoked by physiological vagal activation in man is profoundly inhibited by H2-receptor blocking agents.

Adult↗
PubMed1978

Gastric acid responses to adequate and modified sham feeding and to insulin hypoglycemia in duodenal ulcer patients.

In duodenal ulcer patients the effect of vagal activation of gastric acid secretion by the intricate procedure of adequate sham feeding for 15 min has been compared with the effects of vagal stimulation induced by more easily accomplishable methods. The comparison involved modified sham feeding for 15 min by a 'chew-and-spit' technique and insulin hypoglycemia produced by i.v. injected insulin in the doses 0.1, 0.15, or 0.2 U/kg b.w. In 6 patients the peak and 2-hour acid responses to adequate sham feeding (10.7 mmol/30 min and 29.7 mmol) did not significantly differ from corresponding responses to modified sham feeding (9.1 mmol/30 min and 25.2 mmol). The peak and 2-hour acid responses to insulin in a dose of 0.1 U/kg (8 patients) were not significantly different from the sham-feeding responses. The 2-hour acid responses to insulin in the doses of 0.15 (6 patients) and 0.2 U/kg (17 patients) were significantly higher than the sham-feeding response. Furthermore, the peak acid response to insulin in a dose of 0.15 U/kg was significantly higher than the peak sham-feeding response. The gastric acid responses to modified sham feeding and insulin in a dose of 0.1 U/kg b.w. in duodenal ulcer patients seem to satisfactorily reflect physiological vagal activation of acid secretion.

Duodenal Ulcer↗
PubMed1978

The vagogastrone mechanism in man.

From experiments on the dog evidence has accumulated of vagal release of a candidate hormone inhibiting gastric acid secretion--vagogastrone. The nature and origin of vagogastrone are uncertain. The inhibitory effect of vagogastrone is characteristically exerted against gastrin-stimulated acid secretion from the vagally denervated parietal cell area. In the present study vagal activation by sham feeding significantly inhibited the submaximal acid response to continuous i.v. infusion of pentagastrin in seven duodenal ulcer patients previously subjected to proximal gastric vagotomy. The inhibitory effect was slight--16% reduction--and of short duration. Sham feeding had no effect on the pentagastrin-stimulated acid secretion in six subjects with an intact stomach. The results favour the existence of a vagogastrone mechanism in man, but the inhibitory effect seems to be of quantitatively minor importance, at least in the duodenal ulcer patient.

Adult↗
PubMed1978

Evidence for a defective inhibition of pentagastrin-stimulated gastric acid secretion by antral distension in the duodenal ulcer patient.

Graded antrum distension by 50-, 100-, and 150-ml balloon volumes significantly stimulated gastric acid secretion in 6 duodenal ulcer patients, but had no stimulatory effect in 6 healthy subjects. Antrum distension by 150-ml balloon volume had no effect on the acid response to submaximal stimulation by a continuous intravenous infusion of pentagastrin in the duodenal ulcer patients, but significantly inhibited this response in the healthy subjects. The inhibition by antrum distension in the healthy subjects amounted to 20%. The results suggest that antrum distension elicits stimulatory as well as inhibitory mechanisms in man with inhibition of acid secretion predominating in healthy subjects and stimulation of acid secretion predominating in duodenal ulcer patients. The mechanism of inhibition is unknown.

Adult↗
PubMed1978

The development of "stagnant loop" syndrome following surgery for peptic ulcer disease.

Although gastric resection may cause a variety of functional gastrointestinal disorders, malabsorption is rare. When such a disturbance occurs other complicating factors are mostly involved. Two patients who developed a severe malabsorption after partial gastric resection are presented. They both had the prerequisites for intestinal stasis--one had small bowel diverticula and the other a "blind loop" after previous surgery. Their malabsorption was cured by surgical correction of stasis.

Adult↗
PubMed1978

Mixed endocrine gastric tumors associated with hypergastrinemia of antral origin.

A patient with atrophic gastritis and excessively raised serum gastrin concentrations (4000 to 5000 pg/ml) was found to have multiple polypous tumors of the gastric corpus mucosa. Following gastrectomy, serum gastrin concentrations decreased to undetectable levels. The tumors consisted of a mixed population of endocrine cells. The majority of tumor cells were of the ECL type, but, in addition, enterochromaffin cells of various subtypes as well as agranular cells were found. The tumors were locally invasive and invaded the walls of submucosal blood vessels. The surrounding mucosa showed a severe atrophic gastritis with intestinalization and contained numerous goblet cells, enterochromaffin cells, and cholecystokinin cells. Cholecystokinin cells do not occur in the normal oxyntic mucosa. Hence, the observation of this cell type in intestinalized gastric epithelium suggests that "intestinalization also is associated with changes in endocrine cell populations. Gastrin has been shown to affect the function of the ECL cells. Indications for a trophic action of gastrin on these cells have been obtained. It is discussed whether greatly raised serum gastrin levels in patients with atrophic gastritis may be associated with increased risks for the development of certain types of gastric tumors.

Diabetes Complications↗
PubMed1978

Gastroscopic reduction of afferent loop intragastric intussusception.

A case is presented of afferent loop intragastric intussusception diagnosed by gastroscopy 18 years after partial gastrectomy with retrocolic gastrojejunostomy. The intussusception was successfully reduced by means of the gastroscope. The symptoms were instantly relieved, with a symptom-free follow-up of 1/2 year. Provided that the intussuscepted segment appears viable it seems justified to aim initially to reduce jejuno-gastric intussusception with the aid of the gastroscope.

Aged↗
PubMed1977

Analysis of the actions of cimetidine and metiamide on gastric acid secretion in the isolated guinea pig gastric mucosa.

Cumulative dose-response curves for histamine were determined on acid secretion from the isolated guinea pig gastric mucosa. Two H2-receptor antagonists-metiamide and cimetidine-behaved like competitive antagonists to histamine on gastric acid secretion in vitro. The isolated guinea pig gastric mucosa seems to be a suitable in vitro model for analysing the action of compounds on receptors involved in acid secretion.

Animals↗
PubMed1977

Effect of fundic distension on gastric acid secretion in man.

The effect of distension of the fundus and body of the stomach on gastric acid secretion was studied in 26 patients with duodenal ulcer and six healthy subjects. Graded distension produced by inflating a rubber balloon to volumes of 150, 300, and 600 ml resulted in significant sequential increments of acid output. The secretory response outlasted stimulation by at least one hour. In both groups of subjects, the highest acid output obtainable with fundic distension amounted to just above 50% of the maximum secretory response evoked by intravenous infusion of pentagastrin. A significant correlation was found between the peak secretory rates observed during fundic distension and after pentagastrin stimulation. It is concluded that distension of the oxyntic gland area in man is a potent stimulus for gastric secretion of acid and that patients with duodenal ulcer are no more sensitive to this stimulus than healthy subjects.

Adult↗
PubMed1977

Effect of atropine and proximal gastric vagotomy on the acid response to fundic distension in man.

In four healthy subjects and in 12 patients with duodenal ulcer (DU), graded balloon distension of the gastric fundus and body caused increments in acid output related to the distension volumes. The mean peak distension response amounted to about 50% of the mean peak acid output (PAOpg) evoked by intravenous infusion of pentagastrin in a dose of 300 microng/h, eliciting maximum observed secretory response. During distension with the largest balloon volume, 1-0 mg atropine injected intravenously significantly depressed the acid secretory rate, the median inhibition amounting to about 80%. In two patients with DU, 2-5 mg atropine completely abolished acid secretion during fundic distension. In nine subjects with DU, complete proximal gastric vagotomy profoundly depressed the secretory responses to graded fundic distension, eliminating the acid response to the smallest balloon volume used. A slight, but significant, response to the largest distension volume persisted after complete vagotomy. Incomplete proxomal gastric vagotomy was found to reduce only moderately the distension responses in five patients, and the peak acid response to fundic distension as related to PAOpg remained unchanged. In conclusion, distension of the gastric fundus and body in man stimulates acid secretion by means of an atropine-sensitive, presumably cholinergic, reflex mechanism and the findings after vagotomy are in agreement with the concept that this reflex mechanism is conveyed by both short intramural and long vagovagal pathways.

Adult↗
PubMed1977

The effect of intragastric pH-variations on the gastric acid response to insulin hypoglycaemia in healthy subjects and duodenal ulcer patients.

The gastric acid response to i.v. injection of 0.15 U of soluble insulin/kg b.w. was determined in healthy subjects and duodenal ulcer patients during intragastric perfusion with water, 0.1 M HC1, and alkaline buffer (pH 8.3). Perfusion with hydrochloric acid significantly reduced the peak gastric acid output following insulin in 6 healthy subjects (reduction 45%, p less than 0.05) but had no significant effect on the peak gastric acid response to insulin in 7 DU patients (reduction 16%, p greater than 0.05). The 2.5-hour gastric acid response to insulin was, however, significantly reduced in both groups (56% and 35%, respectively) by exogenous acidification of the stomach. The gastric acid response to insulin hypoglycaemia in 3 DU patients was the same with intragastric water and alkaline buffer perfusion. The reduction of the gastric acid response to insulin hypoglycaemia by intragastric acidification corresponded to a reduced volume secretion and could not be ascribed to increased back diffusion of hydrogen ions or duodenal inhibition. These findings suggest that the gastric acid response to insulin hypoglycaemia is inhibited by a low intragastric pH in man, and that DU patients are less sensitive to the inhibitory mechanism than healthy subjects.

Adult↗
PubMed1977

Effects of fundic distention on pentagastrin-stimulated gastric acid secretion in man.

The acid secretory effect of combined stimulation with balloon distention of the fundus and body of the stomach and intravenous infusion of pentagastrin has been studied in patients with duodenal ulcer (DU) and in healthy subjects. In 8 nonoperated DU subjects and in 5 DU patients subjected to proximal gastric vagotomy, low grade fundic distention moderately enhanced the acid output evoked by a threshold dose of pentagastrin. Fundic distention with a baloon volume eliciting a maximal acid response to distention either left unchanged or suppressed the maximal acid secretory rate produced by pentagastrin in 7 nonoperated and 6 vagotomized DU patients and in 5 healthy subjects. The heterogeneous secretory effects of maximal stimulus combination suggest that fundic distention has a complex action on acid secretion eliciting a hitherto unknown inhibitory effect as well as a cholinergic activation of the parietal cell area. This complex action may explain the failure of fundic distention to augment markedly the action of pentagastrin in the present study.

Adult↗