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Biomedical subjects

K Takagi

Publications and source records attributed to K Takagi.

At least 847 records · Page 47Linked to original sources
PubMed1977

Effects of cimetidine, a histamine H2-receptor antagonist, on various experimental gastric and duodenal ulcers.

The effects of cimetidine, a new histamine H2-receptor antagonist, on the development of experimental gastric and duodenal ulcers were studied. It was found that either by the oral, intraduodenal, or intraperitoneal route this agent had a marked inhibitory activity on stress-, aspirin-, indomethacin-, or histamine-induced gastric ulcers in rats and guinea pigs. The effects of cimetidine on stress-, aspirin-, and indomethacin-induced gastric ulcers were dose-dependent in many cases. Pylorus-ligation uclers, reserpine- or serotonin-induced gastric ulcers were little influenced by cimetidine. Duodenal ulcers induced by continuous infusion of carbachol-histamine were significantly inhibited by a simultaneous infusion of cimetidine. An analysis of gastric contents in pylorus-ligated rats after stressing indicated a decreased volume and acid output as the result of intraduodenal cimetidine treatment. In contrast, cimetidine exerted little influence on gastric secretion in rats treated with aspirin or in guinea pigs treated with histamine. Thus, the mechanism of action of cimetidine in preventing gastric or duodenal ulcers is likely to occur by suppression of gastric secretory function in a duodenal ulcer model but by suppression of other unknown ulcerogenic factors in gastric ulcer models.

Administration, Oral↗
PubMed1977

Influence of aspirin on healing of chronic gastric ulcers in dogs.

Gastric ulcers induced in dogs by transserosal injection of 1 ml of 40% acetic acid healed completely by the 7th week after ulceration and never reulcerated during the observation period up to 12 weeks. Acetic acid ulcers in the active (at 1 week), quiescent (3 weeks) or healed (at 7 weeks) stages were not influenced by the daily administration of aspirin 2 g/dog/day for for 5 consecutive weeks. All examinations were done by gastroscopy in addition to macroscopical and histological observations at autopsy.

Acetates↗
PubMed1977

Purification of histamine receptor, (III) Characterization of receptor rich membrane fraction of small intestinal smooth muscle of the cat.

Intracellular localization of histamine receptors in small intestinal smooth muscle of the cat was studied by investigating distribution of marker enzymes in the receptor rich fraction. Distribution of membrane markers coincided with that of the radiochemically labeled receptor fraction. Membrane fraction was further purified and it was concluded that the histamine receptor rich fraction is mainly composed of cell membrane. The chemical composition of the fraction lent support to this conclusion.

Adenosine Triphosphatases↗
PubMed1977

Effects of metiamide and propranolol on gastric secretion in anesthetized dogs.

The effects of metiamide, a histamine H2-receptor antagonist, and propranolol, a beta-adrenergic blocking agent, on gastric secretion were studied in anesthetized dogs. Metiamide, 1.45 mg/kg i.v., markedly inhibited the gastric secretion induced by a continuous i.v. infusion of tetragastrin (8 microng/kg-hr), histamine dihydrochloride (160 microng/kg-hr), or methacholine bromide (100 microng/kg-hr). Propranolol 0.5 or 1.0 mg/kg i.v. produced a significant potentiation of tetragastrin-induced gastric secretion but no influence of the secretion induced by methacholine. Propranolol at 5 or 10 mg/kg i.v. produced a slight reduction of the tetragastrin-induced secretion and a significant reduction of methacholine-induced secretion. Histamine-induced gastric secretion was not affected by propranolol at either 1 and 10 mg/kg i.v. These findings lend support to the hypothesis that interactions among histamine, gastrin and acetylcholine receptors do occur though the degree would not be the same in all directions.

Animals↗
PubMed1977

Effects of Panax Ginseng root on conditioned avoidance response in rats.

Pole climbing and shuttle box tests were employed to study conditioned avoidance response (CAR) and discrimination behaviour in Wistar male rats given extracts from Panax Ginseng root intraperitonealy. Neutral saponins (GNS), a water soluble fraction (GF4) which does not contain saponins, and a lipid soluble fraction (GNo. 5) inhibited CAR and discrimination ability between 500 Hz sound with electric shock (SD) and 1000 Hz sound without shock (Sdelta). Small doses of GNo. 5 and ginsenoside Rg fraction (GRg) produced a slight shortening of the response latency (RL) to the conditioned stimulus in CAR. GNo. 5 produced the incorrect response to Sdelta. Significant changes in the extinction of CAR were not evident with any fraction. Data from these tests indicate that Panax Ginseng root contains at least three sedative compounds.

Animals↗
PubMed1977

Purification of histamine receptor. (IV) Specificity of binding of various drugs to the histamine receptor-rich fraction and to solubilized binding sites.

Studies were made on tritiated histamine binding to the receptor-rich membrane fraction and solubilized sites and its displacement by various drugs. H1-Agonists and antagonists displaced histamine most effectively. A H2-agonist and atropine were less effective and propranolol, phentolamine and imidazole acetic acid had little effect. The solubilized binding sites showed the same specificity of binding as the membrane fraction. Membrane fragments had two binding constants, whereas solubilized sites had only one. Solubilized sites bound similar amounts of histamine and dibenamine: the latter was applied to intact tissue under conditions which would presumably cause specific binding to histamine receptors. These binding characteristics show that the method used was adequate for purification of histamine receptors from smooth muscle of cat small intestine.

Animals↗