Fasting blood levels of gastrin, somatostatin, and pancreatic polypeptide in peptic ulcer disease

Gastrin, somatostatin and oxytocin levels in patients with functional disorders of the gastrointestinal tract and their response to feeding and interaction

Twenty-four individuals with functional disorders of the gastrointestinal tract participated in the study. Symptoms from the upper and lower gastrointestinal tract were recorded by means of a self-administered questionnaire before, 3 months and 3 yr after participation in group therapy. Blood was sampled from the patients while they were subjected to three different provocations (a friendly greeting, a food stimulus and a stress stimulus). Ten subjects without gastrointestinal symptoms participated in an identical experiment. Gastrin, somatostatin and oxytocin levels were measured with radioimmunoassay. Both gastrin and somatostatin levels were influenced by the provocations and by the greeting and the stress stimulus in particular. In principle, the controls tended to react with a parasympathetic response pattern following the interactive stimuli, whereas the individuals with functional disorders of the gastrointestinal tract reacted with an activation of the sympathetic nervous system. Somatostatin levels were significantly higher and oxytocin levels lower in patients than in controls and gastrin levels tended to be higher in patients than in controls. Most individuals reported both gastric as well as intestinal symptoms. Gastrin levels correlated positively with total symptom level and somatostatin levels with intestinal symptoms scores reported by the patients.

Pancreatic polypeptide response to insulin in duodenal ulcer. Different levels in accordance with ulcer activity and its response to treatment

Pancreatic polypeptide is said to be a marker of vagal tone in duodenal ulcer. To determine whether pancreatic polypeptide levels are related to the course of duodenal ulcer, we studied acid and pancreatic polypeptide responses to insulin in 80 patients with duodenal ulcer disease: 40 with unoperated duodenal ulcer and 40 with proximal vagotomy. Data were analysed in accordance with the presence of an ulcer (active disease) and, when present, in accordance with the ulcer healing on medical treatment (cimetidine, 1 g/day for 4 weeks). In both groups acid and pancreatic polypeptide responses to hypoglycaemia were slightly correlated (r = 0.38) (p less than 0.05). The basal pancreatic polypeptide level was higher in patients with active disease than in those with inactive disease, who had a basal level similar to that of normal subjects of the same age range. Like the insulin-stimulated acid secretion, the pancreatic polypeptide response to insulin hypoglycaemia was higher in patients with active disease than in those with inactive disease (p less than 0.05): 26.1 +/- 3.9 versus 20.1 +/- 4 nmol/l/120 min, respectively, in unoperated patients and 34.8 +/- 2.2 versus 24.3 +/- 2.5 nmol/l/120 min, respectively, after proximal vagotomy. In active disease the pancreatic polypeptide response to insulin hypoglycaemia was higher in subjects whose ulcer did not heal further after cimetidine therapy than in those whose ulcer did. These data suggest that the pancreatic polypeptide response to insulin is an indicator of duodenal ulcer activity and is related to the treatment efficacy. These relationships are partly mediated by increased vagal tone.

The effects of substance P, histamine and histamine antagonists on somatostatin and gastrin release from the isolated perfused rat stomach

Secretion of somatostatin-like immunoreactivity (SLI) from the isolated perfused rat stomach has been shown to be inhibited by substance P. The present study was initiated to examine the possibility that this action of substance P was mediated via release of histamine. Substance P (1 microM) reduced basal secretion of SLI in agreement with earlier studies. Neither pyrilamine nor cimetidine influenced this action. Basal immunoreactive gastrin (IRG) secretion was unaffected by substance P. Addition of pyrilamine during substance P perfusion increased IRG secretion whereas addition of cimetidine resulted in a delayed decrease on removal of both compounds. Histamine (1 and 10 microM) increased SLI secretion and reduced IRG secretion. Pyrilamine increased and cimetidine decreased IRG secretion but neither drug influenced SLI secretion. Pyrilamine had no effect on histamine-stimulated SLI secretion but inhibition of IRG secretion by histamine was converted to stimulation. Cimetidine potentiated histamine stimulation of SLI secretion and inhibition of IRG secretion.

IN CONCLUSION

(1) substance P inhibition of SLI secretion is unlikely to be mediated via release of histamine. (2) The gastrin cell appears to have both H1- and H2-receptors which mediate opposite actions but H1-receptor-mediated inhibition is predominant. (3) Histamine weakly stimulates SLI secretion but there may be both inhibitory and stimulatory pathways acting via H2- and H1-receptors, respectively.

Antral gastrin-producing G-cells and somatostatin-producing D-cells in peptic ulcer

The number of G cells and D cells per area unit and the G cell/D cell ratio was studied in control subjects and patients with duodenal or gastric ulcer. A great inter-individual variation in the population density of both types of cells was observed in the three groups studied. G cell density was significantly decreased in both duodenal and gastric ulcer patients, when compared with controls; whereas no difference in G cell density was seen between duodenal ulcer patients and gastric ulcer patients. However, D cell density was significantly decreased in duodenal ulcer patients when compared with control subjects and gastric ulcer patients. In this latter group, D cell density was also lower than in control subjects. A significant positive linear correlation between G cell number and D cell number was found in the three groups studied. The G cell/D cell ratio was significantly increased in duodenal and gastric ulcer patients when compared with controls. This was mainly due to a decrease in D cell numbers. It is concluded that a local deficit in antral D cells in patients with peptic ulcer may favor the pathogenesis of ulcer disease.

Elevated levels of fasting and glucose-stimulated pancreatic polypeptide in patients with duodenal ulcer

Mean fasting preoperative pancreatic polypeptide levels in a group of 18 patients with duodenal ulcer disease were 462 +/- 88 pg/ml, with 13 patients having markedly elevated levels (mean 600 +/- 106 pg/ml) and 5 patients having normal or minimally elevated levels (mean 112 +/- 32 pg/ml). Mean fasting postoperative pancreatic polypeptide levels significantly decreased to 136 +/- 36 pg/ml, with decreases occurring in 12 of 13 patients who had had markedly elevated preoperative values. Parietal cell vagotomy and truncal vagotomy produced significant reductions in both fasting pancreatic polypeptide levels and in the glucose-stimulated pancreatic polypeptide response during the first 60 minutes. There was no correlation between pancreatic polypeptide levels (fasting and stimulated) and duration of ulcer disease, indications for ulcer operation, type of operation, or age of patient. These results suggest that elevated fasting pancreatic polypeptide levels may indicate vagal hyperactivity in some patients with duodenal ulcer.

Basal and food-stimulated levels of gastrin and pancreatic polypeptide in non-ulcer dyspepsia and duodenal ulcer

Basal and food-stimulated levels of gastrin and pancreatic polypeptide (PP) were studied in 86 patients with non-ulcer dyspepsia (NUD), defined as chronic or recurrent epigastric pain without anatomical antecedents and without concomitant symptoms of irritable bowel. Thirteen patients with endoscopically confirmed duodenal ulcer disease (DU) and 13 healthy subjects constituted the reference groups. The mean basal gastrin concentration was moderately but significantly (p less than 0.05) higher in the NUD group than in the reference groups (24.3 +/- 1.6 (SEM) pmol/l in NUD, compared with 15.0 +/- 1.5 and 13.6 +/- 1.0 pmol/l among DU patients and healthy subjects, respectively). The well-established postprandial hypergastrinemia in duodenal ulcer patients could be confirmed in this study, and their gastrin response to food was significantly (p less than 0.01) greater than the responses observed both in healthy subjects and in NUD patients. The two latter groups did not differ significantly with regard to gastrin increments, but there was a tendency towards greater increases in the NUD group. A significantly (p less than 0.05) enhanced PP response to the test meal was observed among the DU patients, whereas the response pattern in NUD was closely similar to that in healthy subjects.

Vagal tone on the pancreatic polypeptide cell in duodenal ulcer patients. Correction for maximal and minimal secretory capacity

It has previously been suggested that pancreatic polypeptide (PP) might serve as an indicator of abdominal vagal tone in duodenal ulcer (DU) patients. In this investigation we have attempted to study the vagal tone on the PP cells by correcting the basal PP concentrations to the insulin-stimulated (maximal) and atropine-suppressed (minimal) PP responses, to correct for the PP cell mass. There was no statistically significant difference between either the directly measured basal PP concentrations or the basal PP concentrations correlated to maximal and minimal secretory capacity in 10 DU patients and 10 sex- and age-matched controls. The observations indicate that the vagal branches to the PP cells of DU patients do not have higher tone than those of normal subjects.