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Biomedical subjects

M Noma

Publications and source records attributed to M Noma.

80 records · Page 5Linked to original sources
PubMed1986

Chronic infusion of norepinephrine into the ventromedial hypothalamus induces obesity in rats.

To examine whether chronic increase in the local concentration of certain neurotransmitters in the hypothalamus might lead to some metabolic disorders in peripheral organs, several neurotransmitters and neuropeptides were infused continuously at a rate of 0.48 microliter/h for up to 20 weeks into the unilateral ventromedial (VMH), lateral or paraventricular hypothalamic nucleus of rats. A massive obesity with marked increase in body weight was observed after about 10 weeks when norepinephrine (NE) was infused chronically into the VMH, but not into other hypothalamic loci. Plasma insulin level went up markedly at the early stage of NE infusion and remained high during the infusion period, but plasma glucose did not change appreciably. Similar, but less pronounced effects were observed with epinephrine infusion into the VMH. However, other neurotransmitters and neuropeptides tested had no such effects. The NE-induced obese rats showed hyperphagia and an arrhythmic feeding pattern with increased daytime feeding. Chemical composition and the rate of fatty acid synthesis in the interscapular brown adipose tissue (BAT) were also altered after NE infusion into the VMH: although the triglyceride content was increased, the rate of fatty acid synthesis was decreased, indicating that triglyceride turnover in BAT was greatly reduced. The latter observation suggests that energy dissipation in BAT is impaired and this functional abnormality in BAT may also contribute to the development or maintenance of a new type of hypothalamic obesity induced by NE infusion.

Adipose Tissue, Brown↗
PubMed1984

Endogenous indole-3-acetic Acid in the stem of tobacco in relation to flower neoformation as measured by mass spectroscopic assay.

The contents of free indole-3-acetic acid (IAA) and alkali-labile, conjugated IAA were measured in relation to a ;floral gradient' present in epidermis and subepidermis tissues of flowering plants of Nicotiana tabacum by capillary gas-chromatographic spectrometric analysis by selected ion monitoring (GC-SIM-MS) using 2,4,5,6,7-penta deutero IA ((2)H(5)-IAA) as an internal standard. In floral axes, floral branches and stems with floral branches, free IAA levels (dry weight) were 387, 253, and 417 nanograms, and bound IAA levels were 99, 1089, and 268 nanograms. In vegetative tissue of the first plus second internodes (measured from top), and of the 11th to 13th internodes, free IAA levels were 826 and 500 nanograms, and bound IAA levels were 1421 and 286 nanograms, respectively. Since flower-forming ability of excised cells from the epidermis and subepidermis shows a gradient in an in vitro system, but levels of IAA in these tissues do not, there thus appears to be no correlation between flower-forming ability (in vitro) and endogenous IAA levels (at the time of excision) in tobacco stem tissues.

Journal Article↗
PubMed1983

[Fundamental and clinical studies on T-1982 (cefbuperazone) in the field of obstetrics and gynecology].

T-1982 (cefbuperazone), a new cephamycin antibiotic, was fundamentally and clinically studied in the field of obstetrics and gynecology. The following results were obtained. The concentrations of T-1982 in arterial and venous blood and genitalia following intravenous injection were measured. The results demonstrated favourable transfer of the drug into various internal genital organs. T-1982 was administered to 12 patients. The efficacy rate was 75.0%, that is to say, good in 9 cases. No side effects were noted in any cases. It is, therefore, presumed that T-1982 is a useful drug for the infectious diseases in the field of obstetrics and gynecology although the number of subjects was not so large in this study.

Adult↗
PubMed1981

Changes in Endogenous Gibberellins and the Metabolism of [H]GA(4) after Geostimulation in Shoots of the Oat Plant (Avena sativa).

The recovery from "lodging," or bending over, by shoots of 42-day-old Avena sativa plants is controlled primarily by a negatively geotropic differential growth of the lower halves of the p-1 node-pulvinus and the base of the p-1 internode, relative to the upper halves. Although geostimulation causes a significant reduction in p-1 internode length, dry matter accumulation in the p-1 node-pulvinus is increased, apparently at the expense of the sheath. Recovery to an angle of 30 degrees is associated with changes in endogenous gibberellin-like substances (GAs), and in differential metabolism of applied [(3)H]GA(4) (1.4 Curie per millimole). Although geostimulation depressed total GAs (relative to upright plant parts) to 0.40 and 0.13 for node-pulvini and sheaths, respectively, it increased them 2-fold for internodes. Within the plant part geostimulation increased GAs (relative to upper halves) 29- and 7-fold in lower halves of node-pulvini and internodes, respectively, but reduced GAs to 0.3 in lower halves of sheaths. At age 42 days a GA(4/7)-like (nonpolar) substance predominates, with lesser amounts of a GA(3)-like (polar) substance. Native GAs of Avena include GA(3), GA(4), and GA(7). Geostimulation enhanced the ratio of nonpolar to polar GAs for both halves of internodes, but tended to depress it for sheaths and nodepulvini.The disposition and metabolism of applied [(3)H]GA(4) confirmed the above trends for endogenous GAs regarding localization (e.g. up to 2-fold increases in [(3)H]GA(4) and acidic (3)H-metabolites in the lower halves, relative to upper halves). Also, metabolism into highly water-soluble (3)H-metabolites (biologically inactive conjugates?) was greater (up to 1.8-fold) in upper than in lower halves. The end result of such metabolic trends would be to reduce acidic (biologically active?) GAs in the upper half, while retaining them for a longer time in the lower half.Geotropically stimulated Avena shoots thus increase, within 24 hours, the levels of acidic GAs in the lower halves of the p-1 node-pulvinus and p-1 internode, the two plant parts responsible for the geostimulated growth.

Journal Article↗
PubMedDate not supplied

Isolation and properties of platelet-activating factor receptor cDNAs.

The cDNA encoding the platelet-activating factor (PAF) receptor was cloned from a guinea pig lung cDNA library by using a Xenopus laevis oocyte expression system. The human PAF receptor cDNA was isolated from a human leukocyte cDNA library using a 0.8-kbp fragment of the guinea pig PAF receptor cDNA as a probe. Both receptors have the same number of amino acids (342 residues) with seven putative transmembrane spanning domains, and belong to the G-protein-linked receptor superfamily. Overall amino acid identity between the two receptors was 83%:91% in the transmembrane domains. Seven threonine and three serine residues conserved in the cytoplasmic loops of both receptors may function as phosphate acceptors, as related to the homologous desensitization of the receptor. Activation of the PAF receptor yielded inositol 1,4,5-trisphosphate production in the PAF receptor expressed COS-7 cells and oocytes, and guanosine 5'-O-(2-thio)bisphosphate injected into the oocytes inhibited PAF-induced Cl- current, providing evidence that PAF stimulates phosphoinositide turnover via G-protein(s).

Amino Acid Sequence↗