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Biomedical subjects

J Kodama

Publications and source records attributed to J Kodama.

At least 91 records · Page 5Linked to original sources
PubMed1979

Assay methods for prekallikrein and kininogens and their applications.

Prekallikrein activity in plasma was assayed using a synthetic peptidyl fluorogenic substrate (carbobenzoxy-L-phenylalanyl-L-arginine 4-methylcoumarinyl-7-amide), after activation of prekallikrein by acetone and kaolin. For total kininogen assay, the pretreatment of plasma at pH 2.0 was the best to eliminate bradykinin potentiators and kininase activity, before addition of trypsin to convert kininogen to bradykinin. Assay method of high molecular weight (HMW) kininogen was established by conversion of HMW-kininogen to bradykinin through activation of Hageman factor by glass powder and that of low molecular weight (LMW) kininogen was also by treatment of HMW-kininogen-depleted plasma in the same way as that for total kininogen. The marked reduction of prekallikrein and HMW-kininogen, not of LMW-kininogen, was found in pleural fluid of rat carrageenin pleurisy, and in plasma after i.v. injection of bromelain in rats. Members of the pedigree of hereditary angioneurotic edema patients also show low levels of prekallikrein and kininogens in plasma.

Animals↗
PubMed1977

Light-dark patterns in running-wheel activity in rats during chronic administration of theophylline.

Running-wheel activity for 24 hr and activity patterns were studied during chronic theophylline administration. Theophylline altered the normal relations between activity level and illumination. Dark-time activity was decreased to approximately 50% and 24 hr activity was unaffected. These observations were consistent with previous results showing that theophylline suppressed dark-time feeding but had no effect on 24 hr food intake. A possible mechanism to account for these results may be dependent on levels and turnover of brain norepinephrine.

Animals↗
PubMed1976

[A shift to diurnal feeding following chronic administration of theophylline in rats].

Influence of chronic administration of theophylline on feeding behavior in rats was studied in contrast with the saline controls under a 12 hr light-dark cycle. The results obtained were as follows: 1) total amount of food intake per 24 hr was not affected by either chronic administration of theophylline or saline administration; 2) theophyllinized rats, however, ate more food during light time (0900-2100) and less food during the dark (2100-0900); 3) the amount of food intake during the dark in the control group was approximately 80% of total intake, while that in the theophylline group decreased to below 60%; 4) increase in ratios of body weights in the theophylline and the control groups did not differ significantly throughout the entire experimental period. Feeding behavior of the rat is closely correlated with a daily light-dark cycle as was seen in the control group. The feeding circadian pattern disappeared in theophyllinized rats, i.e., the behavioral characteristic of a nocturnal feeder could not be preserved following theophylline administration. The disappearance of the feeding cycle may result from a phase shift of the cycle, which was induced by facilitatory effects of theophylline on food intake during light time.

Animals↗
PubMed1975

Changes of brain serotonin and muricide behavior following chronic administration of theophylline in rats.

Temporal modification of amygdaloid serotonin (5HT) content and the resultant muricide behavior, compared to isolated and olfactory bulbectomized rats, were studied after chronic theophylline administration. Theophylline raised amygdaloid 5HT after Day 28 and amygdaloid 5-hydroxyindoleacetic acid (5HIAA), its deaminated metabolite, after Day 7. Theophylline applied for 29 days elevated 5HT and 5HIAA in the amygdala, the diencephalon and the brain stem, but not in the cortex. Effects of theophylline were reduced latency and maintained tendency to kill, even after overnight muricide test. The 5HT content of the amygdala decreased in bulbectomized rats. Discrepancy between brain 5HT changes and aggressive behavior were discussed.

Aggression↗