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Biomedical subjects

Y Ishihara

Publications and source records attributed to Y Ishihara.

At least 253 records · Page 14Linked to original sources
PubMed1984

Effect of disodium cromoglycate on the action of bronchoactive agents in guinea-pig tracheal strips.

The effect of disodium cromoglycate (DSCG) on the action of various bronchoactive agents was investigated using isolated guinea-pig tracheal strips. DSCG attenuated the acetylcholine-induced contractile responses and shifted the dose-response curve of acetylcholine downward. It also attenuated the histamine-, serotonin-, bradykinin- and PGF2 alpha-induced contractile responses dose-dependently. On the other hand, DSCG potentiated the isoprenaline (isoproterenol)-, epinephrine-, PGE2- and salbutamol-induced relaxation responses, and shifted these dose-response curves downward. Such a shift became dominant by increasing the dose of DSCG. The above results suggest that DSCG might have a direct action on bronchial smooth muscle in addition to the inhibition of the release of chemical mediators from mast cells.

Acetylcholine↗
PubMed1983

Species and strain differences in mepirizole-induced duodenal and gastric lesions.

Species and strain differences in mepirizole-induced duodenal and gastric lesions were studied. Mepirizole at 200 mg/kg given orally induced deep duodenal ulcers and gastric erosions in nonfasted Sprague-Dawley, Fisher, Wistar, and Donryu rats at an incidence of over 75%. Mepirizole at 300 mg/kg given orally also induced penetrating duodenal ulcers in nonfasted rabbits at an incidence of 50%. There was little or no damage to the duodenum and stomach in mice and dogs given 200-300 mg/kg of mepirizole orally or subcutaneously. The stomachs of fasted guinea pigs given 200 mg/kg of mepirizole had superficial erosions at a high incidence (93.3%). Mepirizole at 200 mg/kg given intraduodenally significantly reduced the volume of gastric juice but increased the acidity and pepsin activity in both pylorus-ligated and acute fistula rats. In chronic fistula rabbits, however, the agent at 200 mg/kg given orally reduced the volume and acidity, but increased the pepsin activity. The mechanism of duodenal ulceration by mepirizole differs slightly in rats and rabbits.

Animals↗
PubMed1983

Effect of lipoxygenase inhibitors, AA-861 and T-22083, on chemical mediators released from sensitized guinea-pig lung tissue.

Male Hartley strain guinea pigs weighing about 200g were used as the experimental animals. Histamine and SRS-A released from the lung tissue were measured by the bioassay methods. The amount of histamine released from passively sensitized lung tissue by the challenge of antigen showed marked decrease by preincubating with AA-861 or T-22083, and the percentage inhibition by AA-861 was greater than that by T-22083. The amount of SRS-A released from sensitized lung tissue by the challenge with antigen showed marked decrease by preincubation with AA-861 or T-22083, and the percentage inhibition by AA-861 was greater than that by T-22083. The above results suggest that AA-861 and T-22083 have not only an inhibitory action on the release of SRS-A from sensitized lung tissue but also have an inhibitory action on the release of histamine.

Animals↗
PubMed1983

Carcinogenicity and toxicity tests on p-phenylenediamine in F344 rats.

p-Phenylenediamine, an intermediate of oxidative-type hair dyes, was administered to groups of male and female F344 rats in their diet. A subacute toxicity test showed that 0.4% p-phenylenediamine was very toxic to both sexes, but that 0.2, 0.1 and 0.05% p-phenylenediamine induced no remarkable toxic changes in either sex. In a chronic toxicity test 0.1 and 0.05% p-phenylenediamine were given to both sexes in their diet for 80 weeks, but no carcinogenic effects were found in either sex.

Animals↗
PubMed1983

Effects of antiulcer agents on healing of mepirizole-induced duodenal ulcers in rats.

Healing processes of duodenal ulcers induced by mepirizole and effects of several drugs on the ulcer healing were studied in rats. Mepirizole-induced duodenal ulcers, except for the perforated ones within 3 days after ulceration, gradually diminished in size and depth by the 15th day. Several ulcers persisted for up to 40 days, but complete healing in all rats occurred by the 60th day after ulceration. Oral cimetidine and YM-11170 (both histamine H2-receptor antagonists), at 200 and 30 mg/kg twice daily for 10 days, respectively, significantly accelerated the healing of duodenal ulcers. Oral Maalox (antacid) at 1,000 mg/kg thrice daily and propantheline (anticholinergic agent) at 30 mg/kg twice daily tended to accelerate the healing of the ulcers. Oral 16,16-dimethyl PGE2, at 0.03 and 0.1 mg/kg twice daily, resulted in a delayed healing of the ulcers. Mepirizole-induced duodenal ulcers appear to be a useful model for the study of ulcer healing and for screening of antiulcer drugs.

Aluminum Hydroxide↗
PubMed1983

Identification of group A coxsackieviruses by immune adherence hemagglutination.

We investigated to find whether the immune adherence hemagglutination (IAHA) test could be used for identification of group A coxsackieviruses (Cox. A). By using homogenate of suckling mouse torsos infected with each of nine prototype viruses (Cox. A 2, 3, 4, 5, 6, 8, 9, 10 and 16) and 46 isolates as antigens and hyperimmune mouse ascitic fluids to the prototype viruses, we compared IAHA with complement fixation (CF) for serotyping of these viruses. The results of identification tests by IAHA were the same as those by combined use of CF and neutralization tests on all the 46 strains. By CF alone, however, six of 46 strains were not identified because of lower antigen titers; IAHA antigen titers were generally higher by 16-fold or more than CF tests. Furthermore, IAHA had a higher type-specificity than CF; a weak cross-reaction was found by IAHA only between Cox. A 3 and Cox. A 8. Nonspecific reactions encountered in IAHA were reduced more readily by kaolin than fluorocarbon treatment of the torso homogenates. From these results, we conclude that IAHA is an alternative method to CF and neutralization for serotyping of Cox. A viruses.

Animals↗
PubMed1983

[Experimental studies on distribution of cefotiam, a new beta-lactam antibiotic, in the lung and trachea of rabbits. II. Combined effects with serratiopeptidase].

Plasma levels and distribution in pulmonary and bronchial tissues of CTM following injection into the jugular vein were investigated in rabbits with experimental pleuritis or pneumonitis as well as in normal rabbits. The experiments also included the assessment of the effect of concomitant administration of serratiopeptidase (TSP). The pneumonitis + TSP group, pleuritis group and pleuritis + TSP group showed a tendency to delayed dissipation of CTM from the plasma, as compared with controls. The CTM concentrations in tissues from the apical region of upper lobe (L1), lateral region of middle lobe (L2) and diaphragmatic region of lower lobe (L3) 30 minutes after injection did not differ significantly between the control and the TSP group, pleuritis group or pleuritis + TSP group. In the pneumonitis group, the tissue CTM concentrations at all 3 sites (L1, L2, L3) were lower than those in the control group. They were increased by the concomitant administration of TSP, with statistical significance of increase in regions L2 and L3. Thirty minutes after the injection of CTM, the pneumonitis group and pneumonitis + TSP group displayed essentially comparable CTM levels in pleural fluid, whereas the CTM concentrations in the pleural fluid were prone to be increased in the pleuritis + TSP group as comparing with the pleuritis group. CTM levels in the tissues of trachea (B0), right and left main bronchi (B1) and lobar bronchi (B2) 30 minutes after the injection did not show any significant difference between control and TSP-treated normal groups. CTM concentrations tended to be increased, yet not significantly, in all these regions in the rabbits with pleuritis administered TSP, compared to those without TSP.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗