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Biomedical subjects

F Waldeck

Publications and source records attributed to F Waldeck.

At least 19 recordsLinked to original sources
PubMed1977

Somatostatin mode of action on gastric acid secretion in dogs.

The aim of the present study was to investigate the mode of the inhibitory effect of somatostatin on gastric acid secretion. This was done in Heidenhain-pouch dogs studying the effect of somatostatin on cumulative dose response curves of pentagastrin, carbachol and histamine. Somatostatin inhibited gastric secretion after all three stimuli, with decreasing potency against carbachol, pentagastrin and histamine. The pentagastrin-stimulated acid secretion was inhibited in a noncompetitive way; in contrary to this the carbachol and also the histamine-stimulated secretion was inhibited in a competitive way.

Animals↗
PubMed1977

The relationship between serum IRG levels and LES Pressure under various conditions.

In investigations with various groups of patients there was no correlation between fasting serum IRG levels and LES pressures in individual subjects with undisturbed for disturbed sphincters. After food ingestion a short phase of LES pressure increase (from 13.5 +/- 1.5 to 21.7 +/- 3.8 mm Hg) could be observed. This peak occurs during the phase of rise in gastrin level, but there was no correlation between IRG levels and LES pressure in individual cases. In patients with gastroesophageal reflux we can demonstrate a diminished release of gastrin after a test meal, but there was also a diminished capacity of the LES. In conclusion, in this investigation it has not been possible to show a clear connection in humans between serum IRG and LES function.

Esophageal Achalasia↗
PubMed1977

[Manometry and gastro-esophageal closure mechanism. An attempt at evaluation (author's transl)].

The registration of resting pressures and motility activity has considerably increased our knowledge of the normal functioning of the esophagus. We have not jet solved all the methodological problems of manometry; however perfusion manometry, which is used today, has enabled us to make an exact cassification of functional disorders and adequate therapy. An understanding of the methodological problems involved is necessary for the correct use of the manometric method and the correct interpretation of its results. This precondition has not always been observed, especially in discussion of the gastro-esophageal closure mechanism, and has thu given rie to much confusion. An attempt at a critical evaluation should be the basis for future discussion.

Cardia↗
PubMed1976

Experimental hypergastrinaemia in the dog.

In order to investigate chronic hypergastrinaemia in dogs, studies with various excluded antrum preparations were performed. Gastric secretion was collected from denervated fundic pouches and gastrin levels were measured pre- and postoperatively by radioimmunoassay. In some samples the gastrins were separated according to their molecular size. Distinct hypergastrinaemia and acid hypersecretion developed in dogs where the antrum was excluded by a mucosal septum. Gastrin levels rose to 349 +/- 64 pg/ml (normal 76 +/- 19 pg/ml). Analysis of the gastrin pattern showed a predominance of smaller gastrin components. Although there was marked hypersecretion in most of the dogs with hypergastrinaemia, no close correlation was evident between these parameters. Some of the dogs with hypergastrinaemia developed anastomotic ulcers.

Animals↗
PubMed1976

The effect of intravenous infusion of synthetic human gastrin-I on lower esophageal sphincter (LES) pressure in the dog and its relation to gastrin level.

To demonstrate the relation between gastrin level and lower esophageal sphincter (LES) pressure, experiments with intravenous infusions of synthetic human gastrin-I (SHG-I) were performed in anaesthetized dogs. The results show that infusions with 5 mug-kg-1-h-1 SHG-I have an initially increasing effect on LES pressure but produce unphysiologically high gastrin blood levels. Physiological levels of gastrin were measured only using an infusion dose of 0.5 mug-kg-1-h-1, which was below the threshold for increasing LES pressure.

Animals↗
PubMed1976

Motilin effects on gastrointestinal motility and lower esophageal sphincter (LES) pressure in dogs.

Natural porcine motilin induces phasic contractions of the lower esophageal sphincter in dogs. These contractions are related to gastric contractions, which have the characteristics of interdigestive-motility patterns. Duodenal alkalinization produces an insignificant LES pressure increase after 5 minutes. No effect of motilin was observed when using isolated canine muscle strips.

Animals↗
PubMed1975

The motor-stimulating effect of natural motilin on the lower esophageal sphincter fundus, antrum and duodenum in dogs.

Natural motilin was investigated for its effect on gastrointestinal motor activity in anesthetized dogs. In doses starting from 10 ng/kg as single injection and 100 ng/kg-h as intravenous infusion, motilin induced phasic pressure changes in the lower esophageal sphincter (LES) and in the lumen of the fundus, antrum, and duodenum. Tachyphylaxis was seen in 6 out of 10 dogs. Motilin had no effect on isolated muscle strip preparations of the LES, fundus, antrum, and duodenum in this species.

Animals↗