Uptake and metabolism of myo-inositol by L1210 leukaemia cells.
The initial rate of uptake of [3H]myo-inositol by L1210 murine leukaemia cells is directly proportional to the extracellular concentration and unaffected by several analogues of myo-inositol even at millimolar concentrations. Scyllitol, a geometric isomer of myo-inositol, partially inhibited the uptake of myo-inositol (40% at 0.1 mM). A portion of the uptake of myo-inositol was not inhibited even at 5 mM-scyllitol. At steady-state the intracellular concentration of [3H]myo-inositol is directly proportional to the extracellular concentration. Addition of myo-inositol to medium does not enhance the growth of L1210 cells; these cells can maintain an extracellular concentration of 20 microM-myo-inositol even when grown in myo-inositol-free medium. Synthesis of myo-inositol from glucose by L1210 cells was demonstrated by use of [13C]glucose and m.s. L1210 cells maintain myo-inositol pools by a combination of synthesis de novo and uptake of exogenous myo-inositol by either passive diffusion or a low affinity carrier.
Moyer
J D
JD
Laboratory of Biological Chemistry, National Cancer Institute, Bethesda, MD 20892.
Malinowski
N
N
Napier
E A
EA
Strong
J
J
D000818:Animals; D002855:Chromatography, Thin Layer; D008401:Gas Chromatography-Mass Spectrometry; D007294:Inositol / Q000031:analogs & derivatives / Q000378:metabolism / Q000493:pharmacokinetics* / Q000494:pharmacology; D007424:Intracellular Fluid / Q000378:metabolism; D007939:Leukemia L1210 / Q000378:metabolism; D051379:Mice; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
C009217:scyllitol; D007294:Inositol; C046273:5-deoxyinositol