Thyroid hormone transport in a human glioma cell line

Mol Cell Endocrinol. 1990 Mar 5;69(2-3):157-65. doi: 10.1016/0303-7207(90)90009-w.

Abstract

The uptake of 3,5,3'-triiodothyronine (T3) and thyroxine (T4) was studied in human glioma cells (Hs 683) and compared with that in several other neural cell lines. At 25 degrees C or 37 degrees C, total cell uptake rose rapidly and reached equilibrium within 60 min. The glioma cells had the highest uptake: 47.6 fmol of L-T3 and 43.4 fmol of L-T4 per 10(6) cells at 37 degrees C. These were inhibited 77% and 72%, respectively, by excess unlabeled hormone. Uptake in the nuclei reached equilibrium between 90 and 120 min and was also highest in glioma cells: 1.46 fmol of L-T3 and 0.49 fmol of L-T4 per 10(6) cells. When expressed as percent of total cell uptake, however, glioma cells had the lowest values (3.1% for L-T3 and 1.1% for L-T4). Also in contrast to other cell lines, glioma cells transported L-T4 almost as effectively as L-T3. D-T3 and D-T4 total cell uptake was 86% and 96% lower than that of the respective L-isomers, and the nuclear uptake as a fraction of the cell uptake was similar. Kinetic analysis of the initial rate of cell uptake gave Vmax values for D-T3 and D-T4 that were 97% and 98% lower than for the L-isomers. Antimycin and monodansylcadaverine decreased the Vmax as well as the equilibrium cell and nuclear uptake of the L-isomers. The apparent nuclear affinity constant for L-T4 in intact cells was inhibited 90% in the presence of antimycin, whereas no effect was observed in isolated nuclei.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Comparative Study

MeSH terms

  • Aminoisobutyric Acids / pharmacology
  • Antimycin A / analogs & derivatives
  • Antimycin A / pharmacology
  • Binding, Competitive
  • Biological Transport / drug effects
  • Cadaverine / analogs & derivatives
  • Cadaverine / pharmacology
  • Cell Membrane / metabolism
  • Cell Nucleus / metabolism
  • Glioma / metabolism*
  • Humans
  • Kinetics
  • Medulloblastoma / metabolism
  • Neuroblastoma / metabolism
  • Ouabain / pharmacology
  • Temperature
  • Thyroxine / metabolism*
  • Triiodothyronine / metabolism*
  • Tumor Cells, Cultured

Substances

  • Aminoisobutyric Acids
  • Triiodothyronine
  • antimycin
  • 2-aminoisobutyric acid
  • Ouabain
  • Antimycin A
  • monodansylcadaverine
  • Cadaverine
  • Thyroxine