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T Shohmori

Publications and source records attributed to T Shohmori.

At least 55 records · Page 3Linked to original sources
PubMed1984

Relationship of tyrosine concentration to catecholamine levels in rat brain.

Rats were fed a choline-free low protein diet for 12 or 26 weeks. In the 12-week group, the brain tyrosine concentration did not change. Dopamine levels were low in both the cerebral cortex and striatum. Norepinephrine level was low in the diencephalon. In the 26-week group, the tyrosine concentration was high in the brain. However, the dopamine and norepinephrine levels did not change in the cerebral cortex, striatum and hypothalamus. Furthermore, in another group of rats which were intraperitoneally injected with tyrosine, the brain tyrosine concentration was high, whereas the dopamine and norepinephrine levels in the hypothalamus were not significantly different from control levels.

Animals↗
PubMed1984

Influence of liver injury on the catecholamine metabolism in rat brain.

The present study investigated the brain catecholamine metabolism of rats with liver injury induced either by malnutrition or with CCl4. In the malnutrition group, the plasma tyrosine concentration was low, while it showed a tendency to be high in the cerebral cortex. Dopamine concentrations were low in both the cerebral cortex and diencephalon. Norepinephrine concentrations were low in the cerebral cortex, striatum and diencephalon. Tyrosine hydroxylase activity was elevated while monoamine oxidase activity was decreased in the striatum. In the CCl4 group, tyrosine concentrations in the plasma and cerebral cortex did not change. The dopamine concentration in the cerebral cortex increased five days after, and the norepinephrine concentration in the diencephalon increased 24 h after the last administration of CCl4. These data suggest that catecholaminergic neurons in the brain may be substantially affected by liver injury. It may be considered that malnutrition disturbs brain development, particularly in young rats.

Animals↗
PubMed1982

Determination of p-hydroxyphenylacetic acid in cerebrospinal fluid by high-performance liquid chromatography with electrochemical detection.

Using reversed-phase high-performance liquid chromatography and electrochemical detection with a rapid one-step purification on a Sephadex G-10 column, we have developed a sensitive technique to measure p-hydroxyphenylacetic acid, the oxidatively deaminated metabolite of p-tyramine. The metabolite was measured in cerebrospinal fluid with high recovery and precision. Concentrations of p-hydroxyphenylacetic acid ranged from 4.2 to 17.0 ng/ml with a mean value of 7.8 ng/ml +/- 1.1 SEM in lumbar cerebrospinal fluid of 11 control patients. In a preliminary analysis, the concentrations in schizophrenic patients were significantly lower than those in controls. Since p-hydroxyphenylacetic acid in cerebrospinal fluid seems to be derived from the brain, this finding may indicate a decrease in brain formation. The present method should be useful in clinical investigations to clarify a functional role of p-tyramine in the brain.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1982

Separate detection of glucose-6-phosphate dehydrogenase from 6-phosphogluconate dehydrogenase by DEAE-paper chromatography.

Red blood cell lysates were applied to DEAE cellulose paper for detection of glucose-6-phosphate dehydrogenase. Glucose-6-phosphate dehydrogenase (G-6-PD) was separated from 6-phosphogluconate dehydrogenase (6-PGD) by DEAE-cellulose paper-chromatography and their activities were detected on the chromatogram by applying the reaction mixture. The fluorescence of NADPH formed by G-6-PD was not interfered with by 6-PGD activity. This is a sensitive procedure which detects slight loss of G-6-PD in red blood cells and could be applied to the detection of G-6-PD deficiency.

Chromatography, DEAE-Cellulose↗
PubMed1982

[P-hydroxyphenylacetic acid concentrations in cerebrospinal fluid].

Using reversed-phase high-performance liquid chromatography and electrochemical detection with a rapid one-step purification on Sephadex G-10 column, we have developed a sensitive technique to measure p-hydroxyphenylacetic acid (PHPA), the oxidatively deaminated metabolite of p-tyramine, in cerebrospinal fluid (CSF). The method has been shown to offer simplicity, high sensitivity and low cost for the analysis of PHPA. By using this method PHPA can be measured concurrently with the dopamine metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), in small amounts of CSF (0.5 ml or less). The concentrations of PHPA ranged 4.2 to 17.0 ng/ml with a mean value of 7.8 ng/ml+/-1.1 SEM in lumbar CSF of non-neurological control patients. PHPA value is consistent with the results of earlier studies using different methods. PHPA concentrations in both schizophrenic (4.7+/-0.6 ng/ml, n=11) and epileptic patients (5.8+/-0.4 ng/ml, n=28) were significantly lower than those in control patients. A concentration gradient of PHPA was found along the ventricular-lumbar axis. Probenecid markedly increased PHPA in lumbar CSF. These observations suggest that PHPA in lumbar CSF is derived at least in part from the brain and eliminated from CSF by a probenecid-sensitive transport mechanism. There was a significant correlation between PHPA and HVA concentrations in CSF. This is an interesting finding since a reciprocal relationship between dopamine turnover and p-tyramine concentrations has been found in the striatum of experimental animals. A number of recent studies suggest that p-tyramine may act as neurotransmitter or neuromodulator in specific neuronal systems. The present method should be useful in clinical investigations to clarify a functional role of p-tyramine in the brain.

Adolescent↗
PubMed1981

Galactose and galactose-1-phosphate spot test for galactosemia screening.

A simple spot test to measure galactose and galactose-1-phosphate in blood-impregnated filter paper was studied as a screening test for galactosemia in the newborn. A 3-mm disc punched from blood-impregnated filter paper card was fixed with acetone-methanol and incubated in a reaction mixture containing galactose dehydrogenase and alkaline phosphatase. This reaction mixture was then spotted on DEAE-cellulose paper, dried, and observed under a UV-lamp. The minimum amount of galactose detected by this procedure was 2 mg/dl. Estimation of galactose and galactose-1-phosphate with this procedure correlated well with estimation by bacterial assay.

Escherichia coli↗
PubMed1981

Influence of liver injury on testosterone 5 alpha-reductase activity in the rat diencephalon.

Diencephalon testosterone 5 alpha-reductase activity and plasma testosterone level were measured in the rat with liver injury caused by i.p. administration of CCl4. Testosterone levels in plasma were decreased after CCl4 injection in both group I (0.1ml/150g B.W./once a day for 2 days) and group II (0.01ml/150g B.W./twice a week for three weeks). 5 alpha-Reductase activity in the diencephalon was decreased both on the 7th day after administration in group I and in group II, while being transiently increased on the 1st day after administration in group I. These results suggest that testosterone metabolism in the brain is inhibited during liver disorders.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1980

Effects of thyrotropin-releasing hormone in chronic schizophrenic patients.

The effects of oral and intravenous thyrotropin-releasing hormone (TRH) were studied in 11 male, chronic schizophrenic inpatients in an open trial and a double-blind, crossover design. The general beneficial effects of TRH as assessed on the Brief Psychiatric Rating Scale were not obtained, although improvement of contact, apathy and emotional rapport was observed in a few patients. Serum prolactin, L-triiodothyronine and thyroxine were assayed throughout the study. Since the effects of TRH on behavior were not related to changes in these endocrine factors, the mechanism of action might be independent of its original functions on the pituitary-thyroid axis.

Adult↗
PubMed1979

The effect of insulin on elder phenylketonuric patients.

The effect of insulin on blood phenylalanine, tyrosine and catecholamine levels was investigated in six phenylketonuric patients and eight normal controls. The plasma phenylalanine-tyrosine ratio was lower after insulin injection in five of six patients. In four patients the plasma catecholamine concentrations increased. The tyramine level was remarkably high one hour after insulin injection. Urinary homovanillic acid was elevated in four patients. It appeared that insulin treatment produced some therapeutic effects in patients with smaller phenylalanine-tyrosine ratios or elevated catecholamine levels.

Adolescent↗
PubMed1979

Sex hormones metabolism in the brain: influence of central acting drugs on 5 alpha-reduction in rat diencephalon.

Rats after adrenalectomy-testectomy showed a gradual increase in diencephalon 3-oxo-5 alpha-steroid: (acceptor) delta4-oxidoreductase (5 alpha-reductase) activity for 3 days. The activity then returned near to the normal range on the 4th postoperative day. When rats were given testosterone propionate (TP) 3 days after adrenalectomy-testectomy, diencephalon 5 alpha-reductase activity returned to the preoperative range 2 hr after TP administration. Diencephalon 5 alpha-reductase activity showed a highly significant increase (p less than 0.01) after a single administration of carbamazepine, reserpine, diazepam, phenytoin, phenobarbital or disulfiram. A significant increase (p less than 0.05) was also found after a single administration of methylphenidate, caffeine or methamphetamine. Plasma testosterone decreased concurrently after administration of all these agents, except diazepam. Diencephalon enzyme activity decreased significantly after repeated disulfiram administrations (p less than 0.01) but increased significantly after methamphetamine administrations (p less than 0.05). Plasma testosterone showed a tendency to decrease after repeated methamphetamine administrations but tended to increase after repeated disulfiram administrations.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗