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Biomedical subjects

T Noto

Publications and source records attributed to T Noto.

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

Effect of DL-erythro-dihydroxyphenylserine on the locomotor activity of the mouse.

Effect of dihydroxyphenylserine (DOPS) on the locomotor activity of mice pretreated with beta-phenylisopropylhydrazine was studied using an Animex activity meter. An intraperitoneal injection of DL-erythro-DOPS (200 mg/kg) suppressed significantly the locomotor stimulation by the MAO inhibitor, while DL-threo-DOPS (200 mg/kg) had no effect. Only slight suppression was observed after the administration of 100 mg/kg of DL-erythro-DOPS. Effect of DOPS on the concentrations of brain catecholamines and serotonin of mice pretreated with the MAO inhibitor was also analysed. The administration of DL-erythro-DOPS significantly increased the concentration of noradrenaline, while DL-threo-DOPS did not affect the contents of brain amines in the experimental condition. The suppressive effect of DL-erythro-DOPS on the locomotor stimulation by the MAO inhibitor was confirmed by a simultaneous administration of the amino acid and d-phenylisopropylmethylamine to mice. Based on these findings, the neural mechanisms of the locomotor activity and a clinical application of DL-erythro-DOPS to the manic syndrome were discussed.

Amino Acids↗
PubMed1985

Effect of ethanol and acetaldehyde on the release of arginine-vasopressin and oxytocin from the isolated hypothalamo-hypophyseal system of rats.

Effects of ethanol and acetaldehyde on the release of arginine-vasopressin (AVP) and oxytocin (OXT) were examined using a superfusion system of the isolated hypothalamo-hypophyseal complex of rats. The release of both hormones was significantly suppressed by exposing the tissue samples to Eagle MEM medium containing 1.75 and 2.5% ethanol (the maximal suppression: AVP, 30% and 70%; OXT, 30% and 70%, respectively). However, perfusion with medium containing 3.75 and 5.0% ethanol enhanced the release of OXT during exposure to ethanol (the maximal increase, 1,000%) and the release of AVP was increased markedly just after exposure to ethanol was stopped (the maximal increase, 800%). Perfusion with medium containing 50, 100 and 250 microM acetaldehyde did not affect the release.

Acetaldehyde↗
PubMed1985

Distribution of vasopressin and oxytocin in rat brain.

Arginine-vasopressin and oxytocin in various portions of rat brain were determined by radioimmunoassays. The hormones were extracted from tissue samples into 0.1 N HCl and then purified partially with acetone-petroleum ether extraction. The non-equilibration method was used for the assays. In this method recovery rates of arginine-vasopressin and oxytocin were 73.0 +/- 4.4% and 75.0 +/- 3.8%, respectively. Sensitivities of the assays were 1 pg of arginine-vasopressin and 0.75 pg (0.3 microU) of oxytocin per assay tube. The higher concentrations of arginine-vasopressin and oxytocin were confirmed in the hypothalamo-neurohypophyseal system, where these hormones are synthesized, transported and stored. Relatively high concentrations of these hormones, especially oxytocin, were detected in spinal cord. Amygdala, hippocampus, limbic forebrain and pineal body contained a certain amount of arginine-vasopressin (2-20 pg/mg protein). Oxytocin (1-7 pg/mg protein) was also detected in amygdala, pons and medulla oblongata, pineal body and midbrain. The low concentrations of these hormones were also found in cerebral cortex and cerebellum.

Animals↗
PubMed1984

In vivo alteration in hypothalamic amino acid synthesis during perfusion of ethanol and morphine in unrestrained rat.

In the freely moving rat [U-14C]glucose was microinjected through a guide tube to label a discrete site in the hypothalamus. After 10 min, a push-pull cannula was used to perfuse an artificial CSF within the site at a rate of 25 microliters/min. During the fourth 5 min perfusion of each series, one of three concentrations of either ethanol (94-471 mM) or morphine SO4 (0.13-1.3 mM) was added to the perfusate. Each sample of perfusate was assayed for its content of GABA, glutamate, alanine, aspartate, glycine and glutamine by two-dimensional, thin-layer chromatography. The results show that within a circumscribed region of the dorsal hypothalamus, the synthesis of [14C]glycine and [14C]glutamine was enhanced by ethanol and morphine, respectively. Ethanol generally augmented also the synthesis of GABA, glutamate, and glutamine at sites reactive to the compound. Within the same sites, morphine increased the synthesis of glycine. Other amino acids were not significantly different from the control. Thus, anatomically specific and selective changes in amino acid activity are produced within the rat's hypothalamus in response to the localized presence of ethanol or morphine, suggesting the involvement of certain amino acids in the action of these addictive compounds within the hypothalamus.

Amino Acids↗
PubMed1984

Changes in Ca2+ ion activity within unrestrained rat's hippocampus perfused with alcohol or acetaldehyde.

In the freely moving rat, the kinetics of Ca2+ ion activity were determined at circumscribed sites in the hippocampus, which was perfused with ethanol, tertiary-butyl alcohol or acetaldehyde. Initially, a region in CA1 or other cell field of the dorsal hippocampus was prelabelled by microinjection of 45Ca2+ through a permanently implanted guide tube. Then the tip of a concentric push-pull cannula assembly was lowered through the guide tube to the labelled site, and an isotonic artificial cerebrospinal fluid was repeatedly perfused at a rate of 25 microliter/min. Each perfusion was timed for 5.0 min with a 5.0 min interval between each. Once the washout curve of 45Ca2+ activity had begun to approach its asymptote, ordinarily in the midpoint of a series of perfusions, an isotonic solution of ethanol (188-942 mM), tertiary-butyl alcohol (12-580 mM) or acetaldehyde (10-98 mM) was added to the fourth perfusate. Thereafter, the hippocampal site was again perfused with the normal cerebrospinal fluid for the remainder of the experiment. Although the lowest concentration of ethanol exerted no effect on 45Ca2+ ion activity, an intermediate concentration caused mixed effects in either enhancing or suppressing the efflux into the perfusate of this cation. The highest concentration of ethanol produced in most experiments an initial suppression in Ca2+ ion efflux which was followed frequently by an elevation in the release of 45Ca2+. Similar changes in Ca2+ ion activity were produced by tertiary-butyl alcohol, but the magnitude of its effect was generally less than that of ethanol, suggesting that its effect on brain tissue differs from that of ethanol. Acetaldehyde evoked an intense and concentration-dependent enhancement of Ca2+ ion efflux from the perfused tissue at all of the sites in the hippocampus examined. These results suggest that in the unrestrained rat ethanol could unbind Ca2+ ions from hippocampal membranes or retard their uptake into cells of the hippocampus. The dual excitatory and inhibitory effect of ethanol on Ca2+ ion activity corresponds to the electrophysiological effects of this alcohol and could alter neurotransmitter release from neurons in this subcortical structure. The mechanism of action of acetaldehyde is envisaged to be due to its affinity to membrane sulfhydryl groups which alters protein conformation and thus interferes with both Ca2+ channels and Ca2+ binding properties.

Acetaldehyde↗
PubMed1984

Profile of amino acid synthesis in rat hippocampus during push-pull perfusion of ethanol or morphine.

In the unanesthetized rat, the effect of ethanol or morphine on the new synthesis of six amino acids, gamma-aminobutyrate, glutamate, alanine, aspartate, glycine and glutamine, was determined at circumscribed sites in the hippocampus. In the fasted animal, 5.0 microCi of [U-14C]glucose was microinjected in a volume of 1.0 microliter into a discrete region of the hippocampus through a permanently implanted guide tube. After 10-15 min, the tip of a concentric push-pull cannula assembly was lowered through the guide tube to the labelled site, and an isotonic artificial cerebrospinal fluid was continuously perfused at a rate of 25 microliters/min. Samples of perfusate were collected every 5.0 min in a total volume of 125 microliters. During the fourth perfusion, either ethanol (94 or 471 mM) or morphine (0.1 or 1.0 microgram/microliter) was added to the push-pull perfusate. Amino acids and glucose contained in each sample of perfusate were separated by means of a two-dimensional, thin-layer chromatographic procedure. The results show that the 94 mM dose of ethanol acted only to significantly suppress the new synthesis of alanine. Conversely, the higher 471 mM dose of ethanol significantly increased the new synthesis of both glycine and glutamine from the glucose precursor. The effect of the 0.1 microgram/microliter morphine dose on amino acid synthesis paralleled that of the lower dose of ethanol since it evoked a similar decrease in the synthesis of alanine; however, the higher dose of 1.0 microgram/microliter morphine produced no effect. None of the other amino acids in the hippocampus were affected by either of the CNS depressants. Thus, whereas ethanol seems to exert significant stimulating activity on hippocampal synthesis of glycine and glutamine, morphine and ethanol possess the same inhibitory effect on alanine synthesis in this subcortical structure.

Alanine↗
PubMed1984

[Clinical evaluation of tissue polypeptide antigen in patients with esophageal, stomach and colon cancer].

Serum tissue polypeptide antigen (TPA) levels were measured in 33 patients with esophageal cancer, 39 with stomach cancer and 50 with colon cancer. At the same time five glycoproteins, namely immunosuppressive acidic glycoprotein (IAP), alpha 1-antichymotripsin (alpha 1-ACT), acid soluble glycoproteins (ASP), sialic acid and carcinoembryonic antigen (CEA), were measured for comparison. The mean TPA values were 59.0 +/- 15.4 U/l in 61 normal subjects, 103.6 +/- 104.2 U/l (positive rate, 24.2%) in esophageal cancer patients, 111.9 +/- 49.8 U/l (71.8%) in stomach cancer patients and 124.8 +/- 195.5 U/l (40%) in colon cancer patients. The serum TPA levels in patients with stomach cancer rose with an increased number of involved lymph nodes and with a higher degree of infiltrative growth and increased with the advancement of tumor growth postoperatively. Serum TPA levels correlated well with those of alpha 1-ACT, IAP and ASP in stomach cancer patients and with those of CEA, ASP and sialic acid in colon cancer, but not in esophageal cancer patients. It is suggested that the serum TPA might represent one of the reactant proteins and/or tumor-associated antigens that appear to be dependent upon the cancer status.

Adult↗
PubMed1982

Mechanisms of resistance in Escherichia coli to the sideromycin antibiotic no. 216: isolation and characterization of the resistant mutants.

Escherichia coli easily developed resistance to a new antimicrobial agent of the sideromycin group, No. 216, by spontaneous mutation. Most of the No. 216-resistant mutants tested proved not to be cross-resistant to E. coli phages T1, T5, and ø80. On the other hand, these phage-resistant mutants were cross resistant to No. 216. The initial site for binding of No. 216 to the sensitive cells was located, at the ton A gene product (Ton A-protein) of the outer membrane. However, unlike the phage-resistant mutants, ton A protein (78K-protein) in most No. 216-resistant mutants was intact and these mutants were possessed a particular 87K protein in the outer membrane. It is suggested that No. 216 is taken up by ton A protein and then penetrates into the cell by way of a particular transport system and that a highly mutable portion may exist in this reaction system.

Adsorption↗
PubMed1982

The levels of vasopressin in cerebrospinal fluid of patients with alcoholism.

Concentrations of arginine-vasopressin (AVP) in the cerebrospinal fluid (CSF) of 5 alcoholic patients and 6 healthy volunteers were determined by a radioimmunoassay. The concentrations of AVP in the CSF of alcoholic patients were 2.93-6.17 pg/ml (the mean value, 4.80 +/- 1.34 pg/ml) and those of healthy volunteers 3.80-12.59 pg/ml (the mean value, 9.87 +/- 3.19 pg/ml). The AVP level in the CSF of alcoholics was significantly lower than that of normals (P less than 0.02).

Adult↗
PubMed1982

Thiolactomycin, a new antibiotic. I. Taxonomy of the producing organism, fermentation and biological properties.

A strain of actinomycetes, isolated from a soil sample, has produced a novel antibiotic (C11H14O2S) containing a unique thiolactone moiety in its molecule. On the basis of taxonomic studies the producing organism was identified as belonging to the genus Nocardia. The antibiotic, named thiolactomycin, exhibits a broad antibacterial spectrum and particularly potent activity against Salmonella, Serratia and Bacteroides. Furthermore, the acute toxicity is weak in experimental animals. These results indicate that thiolactomycin is distinct from other known antibiotics and represents a new type of antibiotic.

Anti-Bacterial Agents↗