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Biomedical subjects

T Kariya

Publications and source records attributed to T Kariya.

At least 91 records · Page 5Linked to original sources
PubMed1985

The platelet activation induced by wheat germ agglutinin.

In human platelets, wheat germ agglutinin (WGA) induced serotonin release without cell agglutination. WGA induced the phosphorylation of both 40-kDa and 20-kDa proteins in a parallel manner, and at least, the phosphorylation of 40-kDa protein was preceded by transient formation of endogenous diacylglycerol (DG) accompanied by a decrease in phosphatidylinositol (PI). Both phosphorylation of these two proteins and serotonin release were inhibited by prior treatment of platelets with dibutyryl cyclic AMP, W-7, or TMB-8. These results suggest that both phosphatidylinositol turnover and Ca2+ mobilization play an essential role in WGA-induced platelet activation.

Aminoquinolines↗
PubMed1985

Effect of forskolin on platelet deaggregation and cyclic AMP generation.

The diterpene, forskolin, induced a partial deaggregation of ADP- or collagen-aggregated human platelets in vitro. An increase in platelet cyclic AMP by forskolin was assumed to mediate the platelet deaggregation. PGE1 also deaggregated these platelets, and a combination of forskolin and PGE1 produced deaggregation greater than the maximum which could be obtained with each agent alone. A greater than additive effect was observed on the platelet cyclic AMP level in the presence of both forskolin and PGE1. No additive effect was observed in the phosphorylation of molecular weight (Mr) 21K polypeptide using forskolin (0.1 mmol/l) and PGE1 (5 mumol/l) suggesting that although cyclic AMP is responsible for the deaggregation process a mechanism other than phosphorylation through cyclic AMP-dependent protein kinase may be responsible for the effect of forskolin on platelet deaggregation.

Adenosine Diphosphate↗
PubMed1983

Effects of imipramine on behavior and brain norepinephrine metabolism in tetrabenazine treated rats: comparative study of a single administration with repeated administrations of imipramine.

The effects of a single and repeated administrations of imipramine on the tetrabenazine-induced sedation in rats were studied. The 3-methoxy-4-hydroxyphenylethyleneglycol-sulfate (MHPG-SO4) level in the brain was measured. A single administration of imipramine of 20 mg/kg had no significant effect on the rats' locomotor activity and the brain MHPG-SO4. The administration of 30 mg/kg of tetrabenazine produced marked sedation and significantly increased the brain MHPG-SO4. The imipramine pretreatment reversed the tetrabenazine-induced sedation. The brain MHPG-SO4 in the rats treated with a single administration of imipramine along with tetrabenazine decreased significantly, compared with that in the rats treated with tetrabenazine only. The administration of alpha-methyl-para-tyrosine (alpha-MT) of 250 mg/kg suppressed the reversal of the tetrabenazine-induced sedation. The administration of Ro4-4602 of 50 mg/kg and L-3,4-dihydroxyphenylalanine (L-DOPA) of 100 mg/kg had no significant effect on the reversal. The repeated daily administrations of imipramine of 20 mg/kg reversed the tetrabenazine-induced sedation and produced the locomotor hyperactivity. When the rats were treated with the repeated administrations of imipramine for five days and had tetrabenazine administered on the last day, the brain MHPG-SO4 increased significantly as compared with that in the rats treated with a single administration of imipramine and tetrabenazine. There was no difference in the amount of locomotor activity between the rats administered imipramine of 20 mg/kg and tetrabenazine and those administered imipramine of 40 mg/kg and tetrabenazine. Several considerations were given to the above-mentioned results.

Animals↗
PubMed1983

A comparison of the clinical effects of timiperone, a new butyrophenone derivative, and haloperidol on schizophrenia using a double-blind technique.

The efficacy and safety of timiperone, a new butyrophenone derivative, in schizophrenia as compared with haloperidol were assessed in a multi-clinic double-blind controlled study in a total of 206 patients. The patients were given timiperone (1.0 mg/tablet) or haloperidol (1.5 mg/tablet) in a daily dose of 1--3 tablets for the first day, then up to a maximum of 12 tablets depending on symptoms for 12 weeks. Timiperone was found to be significantly superior to haloperidol in the final global improvement rating and in the general usefulness rating. In the over-all safety rating there were no statistically significant differences between the two drug treatments. With regard to analysis by stratification timiperone was superior to haloperidol in improving abnormal experiences such as hallucination and delusion as well as deficiency of initiative and blunted affect. From these results it is considered that timiperone could be superior to haloperidol in the treatment of schizophrenia.

Adolescent↗
PubMed1983

[Effect of beta-phenylethylamine on locomotor activity and brain catecholamine metabolism in mice].

beta-Phenylethylamine (PEA) is a naturally occurring compound and its structure is close to amphetamine. The effects of PEA on locomotor activity and brain catecholamine metabolism in mice were investigated. Mice were injected with PEA 50 mg/kg intraperitoneally. PEA produced increased locomotor activity between 3 and 6 min, then a decline to 20 min after the injection. There was decreased activity with a slight stereotyped behavior consisted of sniffing and head bobbing between 15 and 20 min. 3-Methoxy-4-hydroxy-phenylethyleneglycol (MHPG), homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) levels in the whole brain were examined. MHPG levels showed no remarkable changes at 5 min after PEA, then increase at 30 and 60 min. HVA level was increased but DOPAC level was decreased at 60 min. Type B monoamine oxidase activity showed no remarkable changes in discrete regions of the brain at 5 and 30 min. These results suggest that PEA may not only release catecholamines but inhibit the reuptake of neurogenically released dopamine.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1980

Growth and lipemic activity of 19-oxo-androstenedione: a potential growth stimulant for poultry.

A metabolite of androstenedione, 19-oxo-androstene-3,17-dione (19-oxo-A), was evaluated for its effects upon growth, oviductal weight, and plasma lipids of young chicks; estradiol benzoate (EB) was used as reference standard. Ten-day-old Leghorn pullets were treated subcutaneously with either olive oil vehicle, EB at .05 to 1.35 mg/kg/day, or 19-oxo-A at 1 to 30 mg/kg/day at 1/2-log dose concentrations for six days. At the highest dose levels of each compound, the relative potency for these biological responses was compared with EB equated to 100. The 19-oxo-A was 100% of EB for body weight gain, 1.4% for oviductal growth, and 10.1%, 2.6%, and 6.2% in elevation of plasma lipids for cholesterol, triglycerides, and phospholipids, respectively. In an antiogonadotropin assay using the hemicastrate rat, only 19-oxo-A suppressed ovarian weight without significant increase in uterine weight. Additionally, this compound did not bind with androgen, estrogen and progesterone cytosol receptor preparation. 19-oxo-A resembles estrogen in inducing growth of poultry, but differs markedly from estradiol benzoate in being essentially devoid of systemic estrogenicity. Thus, 19-oxo-A represents a new and unique steroid for stimulating growth and fat deposition in commercial meat poultry.

Androstenedione↗