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Biomedical subjects

G Bertaccini

Publications and source records attributed to G Bertaccini.

At least 181 records · Page 10Linked to original sources
PubMed1978

The effects of stimulants and inhibitors of histamine receptors on acid secretion from guinea pig gastric fundus.

Two selective H2 receptor stimulants (5-methyl-N-methylhistamine and dimaprit) so far never tested in isolated gastric preparations, were found to be strong stimulants of acid secretion from the guinea pig isolated gastric fundus. Although some differences were observed in the cumulative dose--response curves for these two agonists, the peak responses obtained were not significantly different from the maximum response to histamine. Cimetidine produced parallel displacement of the dose--response curves to the right with the maximum response unchanged, suggesting competitive antagonism of H2 receptors. The dose--response curve for histamine was not affected by the simultaneous administration of an H1 receptor agonist, 2(2-aminoethyl)thiazole, or of an H1 receptor antagonist, pyrilamine. This indicates that the action of histamine on the isolated guinea pig gastric fundus is associated exclusively with H2 receptor stimulation.

Animals↗
PubMed1978

[Action of some gastric antisecretory drugs on histamine H2-receptors (author's transl)].

A series of compounds endowed with gastric antisecretory activity were examined for their possible effects on histamine H2 receptors in different experimental conditions. The data obtained suggest that, apart from cimetidine, all the other compounds are devoid of antagonistic properties on H2 receptors. The inhibitory effect observed in some of the examined preparations is probably connected with unspecific actions.

Animals↗
PubMed1978

[Effect of 2-(5-methyl-4-imidazolyl)-1-methylethylamine on histamine receptors].

Compound 2-(5-methyl-4-imidazolyl)-1-methylethylamine was tested on different preparations for its histamine-like activity. It was found to markedly affect H2 receptors and at the same time to be practically devoid of any activity on H1 receptors. This high selectivity of action indicates that this compound may represent a useful tool for characterizing the distribution of H2 and H1 receptor sites.

Airway Resistance↗
PubMed1977

Action of some natural polypeptides on the longitudinal muscle of the guinea pig ileum.

The structure--activity relationship of some natural tachykinins was investigated in the longitudinal muscle of the guinea pig ileum. The order of potency was eledoisin greater than uperolein greater than substance P greater than phyllomedusin greater than physalaemin. This ratio of activity is different from that observed in other experimental conditions, and in different in vivo or in vitro preparations; it is suggested that the N-terminal part of the molecule of the tachykinins plays a role in determining the degree of potency of these compounds.

Animals↗
PubMed1977

Action of some natural peptides on the stomach of the anaesthetized rat.

Different peptides of natural origin were studied for their stimulant activity on the stomach of the anaesthetized rat. The group of the tachykinins (substance P and its analogues) showed a noticeable spasmogenic activity on the whole stomach from the fundus to the pylorus. Threshold doses ranged between 0.1 and 5 microgram/kg by i.v. route and the order of potency was: eledoisin greater than phyllomedusin greater than physalaemin greater than uperolein greater than substance P. A good correlation between the dose and the duration of the spasmogenic effect was always observed and tachyphylaxis never occurred. Experiments carried out with different kinds of inhibitors suggested that tachykinins act directly on the smooth muscle of the stomach. Taking into account also results obtained in other experimental conditions it was possible to state that the N-terminal part of the molecule of these peptides has a certain importance in determining the degree of their potency in the different tests. The peptide motilin, which does not belong to the family from a chemical point of view, was scarcely active, if at all, in modifying the motility of the rat stomach.

Animals↗
PubMed1976

Inhibitory effect of a caerulein-like peptide on human gastric secretion.

A synthetic heptapeptide corresponding to the C-terminal heptapeptide of caerulein but characterized by a nor-leucyl residue replacing the methyonyl residue of caerulein, when given by i.v. infusion (2 mug/kg/h), inhibited by 70-80% pentagastrin (4 mug/kg/h)-stimulated gastric secretion...

Adult↗
PubMed1976

Biological activities of a new specific stimulant of histamine H2 receptors.

Compound N-methyl-2-(5-methyl-4-imidazolyl)ethylamine (5-methyl-N-methylhistamine) was submitted to a thorough pharmacological examination and was found to be a potent stimulant of H2 receptors, devoid of any appreciable effect on H1 receptors. Because of its high degree of specificity it therefore seems to represent an interesting drug to be used in clinical gastric secretory tests and an useful tool for the study of histamine H2 receptors.

Animals↗