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Biomedical subjects

S Domschke

Publications and source records attributed to S Domschke.

At least 127 records · Page 7Linked to original sources
PubMed1975

Cyclic-AMP and pancreatic bicarbonate secretion in response to secretin in dogs.

In anesthetized dogs given secretin intravenously in doses doubling every 60 min and ranging from 0.5 to 8 units per kg body weight per hr, cyclic-AMP levels in pancreatic tissue rose continuously, whereas DNA concentrations were slightly decreased. Bicarbonate concentrations and bicarbonate outputs, cyclic-AMP tissue concentrations and bicarbonate outputs, as well as cyclic-AMP tissue concentrations and juice outputs, were significantly correlated. In conscious pancreatic fistula dogs, there was also a significant correlation between cyclic-AMP and bicarbonate concentrations and outputs in the pancreatic juice after stimulation by exogenous secretin. Accordingly, enhanced release of endogenous secretin achieved by intraduodenal acidification led to a dose-dependent increase in bicarbonate and cyclic-AMP outputs in both conscious and anesthetized dogs. Phosphodiesterase inhibitors (aminophylline, caffeine, and papaverine) given alone to the conscious dogs did not initiate pancreatic bicarbonate secretion, but they potentiated bicarbonate responses to exogenous secretin. These data suggest that cyclic-AMP plays a part in secretin-stimulated pancreatic secretion.

Aminophylline↗
PubMed1975

Effects of 13-nle-motilin in man--inhibition of gastric evacuation and stimulation of pepsin secretion.

In 3 healthy male volunteers, graded doses of 13-norleucine-motilin (13-nle-motilin)--synthetic analogue of motilin and biologically equivalent to the natural polypeptide--were given intravenously on separate days. Gastric emptying, as determined by means of a radioisotope method, was slowed down dose-dependently by increasing doses of 13-nle-motilin. This was indicated by increasing "half-lives" and "starting indices" of the gastric emptying process, and by decreasing pyloric loss rates, respectively. The gastric pepsin output rose markedly from the basal level during intravenous infusion of 13-nle-motilin.

Adult↗
PubMed1975

Dermatitis herpetiformis and small intestinal lesion--no strict association in german patients.

Dermatitis herpetiformis (DH) has been reported to be associated with various degrees of intestinal villous atrophy in 19 to 68 percent of the cases studied. This was true particularly in British and American populations. The present investigation deals with morphological and functional characteristics of small intestinal mucosa in a group of German DH patients (n=16): No case of villous atrophy could be detected, whereas interepithelial lymphocytes were shown to be slightly but significantly elevated. Intestinal disaccharidase activities were not statistically different from those of healthy control subjects, and oral lactose tolerance tests were normal in each of 8 patients tested. Genetical and immunological differences between our DH patients and those studied by British and American authors may be responsible for the basically different results as to "dermatogenic enteropathy".

Adult↗
PubMed1975

Analysis of the motor effects of 13-norleucine motilin on the rabbit, guinea pig, rat, and human alimentary tract in vitro.

Motor effects of 13-norleucine motilin (13-Nle-M), a synthetic analog of motilin and biologically equivalent to the natural polypeptide, on the rabbit, guinea pig, rat, and human alimentary tract were investigated in vitro. Whereas guinea pig and rat preparations proved refractory to 13-Nle-M action, muscle strips of the stomach and upper small intestine from rabbits and man were highly sensitive to 13-Nle-M, contractile responses being elicited with concentrations of less than 2 times 10-minus 9 M. Although circular muscle from rabbit colon responded to 13-Nle-M, Taenia coli preparations were unaffected by the polypeptide; in man, the reverse was observed. Gallbladder, uterine, and vascular smooth muscle were unresponsive to 13-Nle-M. Pharmacological analysis revealed that the effects of 13-Nle-M on the gastrointestinal muscle are not mediated via nervous pathways: ganglion blockade by hexamethonium, blockade of axonal conduction by tetrodotoxin, or anticholinergic action by atropine failed to affect 13-Nle-M actions. It was therefore concluded that 13-Nle-M caused contractions by stimulating receptors on or in the muscle cell. By use of the antihistaminic pheniramine, histamine receptors could be differentiated from the site of 13-Nle-M action. As the contractile response to 13-Nle-M was abolished by the Ca++ antagonistic compound verapamil, a role for 13-Nle-M in the transport of Ca++ to the cytosol of intestinal smooth muscle might be considered.

Acetylcholine↗
PubMed1975

Protein synthesis in human gastric mucosa: effects of pentagastrin, secretin, and 13-nle-motilin.

This study in man (n = 35) deals with the effects of in vivo administration of pentagastrin, synthetic secretin, and 13-norleucine-motilin (13-nle-motillin), respectively, on the in vitro incorporation of 14C-leucine into gastric mucosal protein. From the results presented it may be concluded that pentagastrin has a trophic influence on gastric mucosa in man, too, while protein synthesis in human duodenal mucosa remains unaltered. As the incorporatin of 14C-leucine into gastric mucosal protein is inhibited both by secretion and 13-nle-motiln, it may be hypothesised that secretin and motilin act as functional antagonists of gastrin in the regulation of human gastric mucosal protein synthesis.

Adult↗
PubMed1975

[The mode of action of bisacodyl on the smooth muscle of the small and the large intestine of the guinea pig].

4,4'-Diacetoxy-diphenyl-(pyridyl-2)-methan (Bisacodyl, Dulcolax, 12--240 mug/ml) was shown to initiate dose-dependently contracile responses in the guinea pig isolated terminal ileum and taenia coli (a preparation of pure longitudinal muscle fibers). In contrast to muscle contractions induced by 1 mug/ml acetylcholine (ACh) and 1 mug/ml histamine, respectively bis-acodyl-induced contractile responses were antagonized neither by the anticholinergic agent atropine (6 mug/ml) nor by the antihistaminic compound pheniramine (6 mug/ml). On the other hand, bisacodyl inhibited contractile responses induced by ACh or histamine in a dose-dependent manner. The possibility that bisacodyl-induced contractions were due to a fall in cyclic 3,5-AMP level was excluded by estimation of endogenous cyclo-AMP. Since exogenous cyclic 3,5-AMP (which should possess calcium-antagonistic properties in smooth muscle) as well as verapamil (a calcium inhibitor) inhibited bisacodyl-induced contractions, a site of action on the calcium-dependent contractile system of the smooth muscle cell was discussed. Furthermore, bisacodyl should diminish the sensibility of the contractile system to other contractile compounds (ACh, histamine).

Acetylcholine↗
PubMed1975

Treatment of duodenal ulcer with a long-acting synthetic secretin: a pilot trial.

In three male duodenal ulcer patients, the effects of a 4-week treatment with a long-acting synthetic secretin -- daily s.c. administrations of 10 clinical units secretin/kg b.w. -- were assessed symptomatically, endoscopically, immunologically, and by means of gastric and pancreatic secretory analyses. Improvement in epigastric pain was noted within a few days following the onset of secretin therapy. In all cases, duodenoscopy revealed complete healing of ulcers after a 2- to 3-week treatment period. Before therapy, cutaneous anaphylactoid reactions due to intradermal injections of secretin could be elicited in each subject; skin reactions were found mitigated after 4 weeks of therapeutic secretin administration thus suggesting some desensitisation. Neither gastric acid secretion nor pancreatic bicarbonate production were substantially influenced by the 4-week course of secretin therapy; consequently, prevention of ulcer relapse is rather unlikely to be achievable with the conditions employed in this study. However, it seems therapeutically promising that the duodenal ulcers under study showed complete healing already after 2-3 weeks of secretin administration.

Adult↗