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Biomedical subjects

T Miyauchi

Publications and source records attributed to T Miyauchi.

At least 289 records · Page 16Linked to original sources
PubMed1982

Effect of acute and chronic treatment with tricyclic antidepressants on 3-methoxy-4-hydroxyphenylethyleneglycol sulfate (MHPG-SO4) contents in various regions of rat brain.

1. Effects of acute and chronic treatment with desipramine (DMI) and amitriptyline (AMI) on 3-methoxy-4-hydroxyphenylethyleneglycol sulfate (MHPG-SO4) levels in eight brain regions were examined in rats. 2. A single injection of DMI decreased MHPG-SO4 levels in all brain regions except the midbrain, whereas the effect disappeared after the chronic treatment except in the septal area. MHPG-SO4 levels in the hippocampus and thalamus were increased after the chronic treatment with the drug. 3. A single and chronic administration of AMI decreased MHPG-SO4 levels in the thalamus and hippocampus, respectively. 4. These results indicate that the effects of acute and chronic treatment with the tricyclic antidepressants on the central noradrenergic systems differ in different regions of rat brain.

Amitriptyline↗
PubMed1982

Receptors for peanut agglutinin isolated from cell lines of human Burkitt lymphoma, lung squamous cell carcinoma and gastric signet ring cell carcinoma.

By affinity chromatography on peanut agglutinin-agarose, receptors for peanut agglutinin were isolated from three lines of human malignant cells labeled with [3H]-galactose. The cell lines examined were a Burkitt lymphoma line Daudi, a lung squamous carcinoma QG-56 and a gastric signet ring carcinoma KATO-III. The isolated receptors from the three sources had similar properties and behaved as glycoproteins with apparent molecular weights of 160,000 to 280,000 upon sodium dodecyl sulfate gel electrophoresis. However, they showed molecular weights of only around 70,000 upon gel filtration, suggesting that they contained large amounts of carbohydrates. Pronase digestion depolymerized the glycoproteins, though significant amounts of the products were large enough to be excluded from a column of Sephadex G-50. The large molecular weight products were not detected when the receptors were treated with mild alkali and NaBH4 prior to pronase digestion. Major components of the radioactive oligosaccharides and glycopeptides released in the latter case had molecular weights in the range from 3,500 to less than 1,000. These results indicate that the glycoprotein receptors had clusters of oligosaccharide chains of small and medium sizes.

Adenocarcinoma, Mucinous↗
PubMed1981

Effects of antidepressants in the rat forced swimming test.

Effects of antidepressants and other drugs on the behaviour of rats in the forced swimming test were examined. Acute and chronic administration of antidepressants reduced the duration of immobility during the first 5 or 10 min of a 30 min test by prolonging escape-directed behaviour which appeared only during this period. However, the drugs did not affect the duration of immobility during the last 20 or 25 min, when the rats were in a state of almost complete immobility. In contrast, methamphetamine, caffeine and scopolamine reduced the duration of immobility not only during the first 5 min but also the next 15 or 25 min without prolonging the escape-directed behaviour but by increasing general motor activity. The effect of antidepressants was potentiated by chronic treatment as compared to acute administration. In the chronic experiments, a significant reduction in the duration of immobility was first observed on the 6th day of the treatment. Although a single injection of diphenhydramine caused an effect similar to antidepressants, this effect disappeared after chronic treatment. These results indicate that immobility itself is not affected by antidepressants. However, it is suggested that the reduction in the duration of immobility only during the first 5 min of the test, which was caused by the prolongation of the escape-directed behaviour, and the potentiation of the effect after chronic treatment are an action specific to antidepressants.

Animals↗
PubMed1981

Androphilic proteins in the human prostate.

Dihydrotestosterone-binding protein in cytosols from human prostates was different from the R1881- and R5020-binding proteins. The R1881- and R5020-binding proteins in the cytosol were very similar and most of the binding sites for R1881 were capable of binding R5020. However, nuclear extracts showed equal binding to dihydrotestosterone and R1881, but not to R5020, suggesting that there might not be a progestin receptor in the human prostate. Maximum binding sites to dihydrotestosterone, R1881, and R5020 in cytosols were very similar among "normal" and pathological prostates except that dihydrotestosterone binding was higher in "normal" prostates than in the pathological ones. Histochemically, R1881-binding was observed in the epithelial cells and in malignant cells, but not in the stroma.

Androgen-Binding Protein↗
PubMed1981

Further studies on the potentiating effect of lithium chloride on methamphetamine-induced stereotypy in mice.

To study the mechanism of the potentiating effect of lithium chloride (LiCl) on methamphetamine (MA)-induced stereotypy in mice, effects of various drugs on the action of LiCl on the stereotypy and pharmacokinetics of MA in different brain regions and liver were examined. The potentiating effect of LiCl disappeared in mice pretreated with atropine or scopolamine whereas LiCl potentiated the stereotypy in mice pretreated with p-chlorophenylalanine, alpha-methyl-p-tyrosine, nialamide, physostigmine or butylscopolamine. The concentrations of MA in the striatum, brainstem and liver were increased and the half-life of MA in these tissues was prolonged by LiCl. The effect of LiCl on the kinetics of MA in the brain, but not that in the liver, was blocked by scopolamine. LiCl prolonged the half-life of MA in the brain and liver in mice treated with physostigmine or butylscopolamine. The inhibition of MA elimination from the brain and its blockade by scopolamine seem to explain the potentiating action of LiCl on the stereotypy and the antagonism by scopolamine of the behavioural action of LiCl, respectively.

Animals↗
PubMed1981

Carcinoembronic antigen and endocrine response in a patient with Sipple's syndrome following surgery.

Circulating carcinoembryonic antigen (CEA), calcitonin (CT) and adrenocorticotropic hormone (ACTH) and levels in tissue extracts of a patients with Sipple's syndrome were measured simultaneously. Biofocal medullary carcinoma of the thyroid gland (MCT), left adrenal phaeochromocytoma and ectopic para-aortal phaeochromocytoma had been removed in the first operation. Total thyroidectomy was performed thereafter. Evidence has been presented showing that (1) the first operation lowered the elevated serum levels of CEA and CT, and levels of CEA and CT in tissue extracts of MCT were considerably higher than those of tumor-uninvolved thyroid tissue and phaeochromocytomas; (2) markedly elevated levels of plasma ACTH were normalized by the first surgery and, in addition, immunoreactive ACTH and beta-melanocyte stimulating hormone (beta-MSH) were detected in the phaeochromocytomas removed. This is a documented case of the simultaneous production of CT and CEA by MCT associated with ectopic secretion of ACTH and beta-MSH from the phaeochromocytomas without manifesting clinical features of Cushing's syndrome and is based on the findings referred to above.

Adrenal Gland Neoplasms↗