Biomedical subjects

K Itaya

Publications and source records attributed to K Itaya.

46 records · Page 3Linked to original sources

PubMed1976

Stereospecificity of conversion of uric acid into allantoic acid by enzymes of Canadida utilis.

1. Allantoinase [EC 3.5.2.5] was isolated from cells of Candida utilis and unpurified by chromatography on columns of DEAE-cellulose and Sephadex G-200 after treatment with urea to remove urate oxidase [EC 1.7.3.3.]. 2. The purified allantoinase catalyzed the hydrolysis of allantoin into allantoic acid. However, only half of the allantoin produced from uric acid by urate oxidase was converted. The rest of the allantoin was unchanged, and showed a negative optical rotation. 3. On the other hand, the combined action of crude urate oxidase and allantoinase resulted in nearly complete conversion of uric acid into allantoic acid. Furthermore, the unpurified allantoinase preparation hydrolyzed racemic allantoin to allantoic acid completely. 4. These results indicate that the urate oxidase produces racemic allantoin from uric acid and that the allantoinase attacks only allantoin of positive optical rotation. The results also suggest that allantoin racemase is present in the yeast cells.

Amidohydrolases↗

PubMed1976

[Studies of gamma-oryzanol (1). Effects on stress-induced ulcer].

In clinical trials, it is well known that gamma-oryzanol is effective against the syndromes of autonomic nervous unbalance and climacteric disorders. The authors studied the action of gamma-oryzanol on restraint, water-immersion stress ulcer under various conditions in rats. The drug, given 1 to 100 mg/kg s.c. daily for five days, reduced the ulcer index dose-dependently, and slightly prevented the rate of increase in serum level of 11-OHCS. These effects were observed in adrenalectomized as well as sham operated rats. It is likely that the antiulcerogenic action of gamma-oryzanol is due to participation of the autonomic nervous system, but not the hypophyseoadrenal axis.

11-Hydroxycorticosteroids↗

PubMed1976

[Studies of gamma-oryzanol. (2) The antiulcerogenic action].

Investigations were performed in male Wistar rats to determine the effects of gamma-oryzanol on circadian rhythm of stress ulcer and on various kinds of experimental ulcers, and the modification of antiulcerogenic action of this drug when combined with the inhibitors or precursors of amine metabolism. Circadian rhythms were observed in stress ulceration with a peak at 2 : 00 p.m. and a reduction at 8 : 00 p.m. The inhibitory action of gamma-oryzanol was significant when stress was loaded for 6 hr from 2 : 00 a.m., 5 : 00 a.m., 11 : 00 a.m. or 2:00 p.m. An 8-day treatment with gamma-oryzanol, 100 mg/kg, s.c., showed a significant inhibition of fasting ulcer, while the 5-day pretreatment exerted slight effects on ulcers by pylorus-ligation or stress-atropine. A 10-day treatment with the same dose of gamma-oyzanol in acetic acid ulcers lowered the serum level of gastrin. Treatment with reserpine, alpha-MT or PCPA prior to stress loading abolished the anti-ulcer effect of gamma-oryzanol, 100 mg/kg, s.c. for 5 days in stress ulcer. Treatment with L-DOPA or 5-HTP revealed a tendency toward restoration of the anti-ulcer effect of gamma-oryzanol. It is suggested that the monoaminergic neuron system is involved in the anti-ulcer action of gamma-oryzanol.

5-Hydroxytryptophan↗

PubMed1975