Early decrease of 2-deoxy glucose and alpha-amino isobutyric acid transport are among the first events in...

Murine erythroleukemic cells were induced to differentiate along the erythroid pathway by Me2SO and HMBA. These inducers caused an early decrease in the transport of glucose and amino acids, both in non-synchronized and in synchronized cultures. Careful analysis of the transport parameters in synchronized cultures showed a cyclic fluctuation of the Vmax but no significant change of the Km. in the presence of the inducers, however, a modification of the Km and Vmax of both carriers was observed which was not dependent on cell cycle. This modification is very early and procedes the transient arrest of the cells in G1 reported previously. In addition, a Me2SO-resistant cell line (DR10) does not show any changes in the transport of glucose and amino acids when incubated with Me2SO. However, there is an effect on the transport when incubated with HMBA which induces differentiation of 50% of the cells. These data support the hypothesis that an early effect of the inducers on the plasma membrane may be a necessary prerequisite for initiation of differentiation in murine erythroleukemic cells.