Pathways of dephosphorylation of 1D-myo-inositol 1,4,5-trisphosphate in GH3 pituitary tumour cells

  1. Ruiz-Larrea, F. 2
  2. Drummond, A.H. 1
  1. 1 University of London
    info

    University of London

    Londres, Reino Unido

    ROR https://ror.org/04cw6st05

  2. 2 Centro Nacional de Biotecnología
    info

    Centro Nacional de Biotecnología

    Madrid, España

    ROR https://ror.org/015w4v032

Revista:
Biochimica et biophysica acta

ISSN: 0006-3002

Año de publicación: 1993

Volumen: 1178

Número: 1

Páginas: 63-72

Tipo: Artículo

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DOI: 10.1016/0167-4889(93)90110-B PMID: 8392378 SCOPUS: 2-s2.0-0027259474 GOOGLE SCHOLAR

Otras publicaciones en: Biochimica et biophysica acta

Resumen

Previous work in [ 3H]inositol-labelled GH3 pituitary tumor cells stimulated with thyrotropin-releasing hormone (TRH) reported the existence of at least ten distinct [ 3H]inositol-containing substances which were identified as different inositol moni-, bis- and tris-phosphate isomers [1]. Here a complete kinetic study of the dephosphorylation pathways of the second messenger Ins(1,4,5)P 3 is reported in GH3 cell homogenates, identifying a new intermediate, Ins(4,5)P 2, in the metabolism of the second messenger. In vitro results obtained with exogenous substrates are compared with in vivo results obtained measuring levels of the endogenous [ 3H]-inositol-labelled isomers that participate in the dephosphorylation pathways of Ins(1,4,5)P 3 in resting and TRH-stimulated GH3 cells. The effect of Li + on the activity of the different phosphatases involved in these pathways is studied as well.