Transport of 6‐deoxy‐D‐glucose and D‐xylose by untransformed and SV40‐transformed 3T3 cells

Transport rates of the nonphosphorylated D‐glucose analogs 6‐deoxy‐D‐glucose and D‐xylose were measured in quiescent and serum‐stimulated cultures of mouse 3T3 cells, in SV40‐transformed 3T3 cells (SV101), and in a density revertant cell line derived from SV101 (Fl‐SV101). Initial rates of both entry and exit of 6‐deoxy‐D‐glucose and D‐xylose were more than threefold higher in serum‐stimulated 3T3 and in SV101 cells than they were in quiescent 3T3 cells, but transport rates were not higher in the transformed cells (SV101) than they were in serum‐stimulated 3T3. Confluent cultures of Fl‐SV101 showed lower rates of transport than serum‐stimulated Fl‐SV101, but not as low as quiescent 3T3 cells. These data confirm previous findings of others with other analogs that glucose transport is one of the cell functions that is depressed when 3T3 cells enter the quiescent G₀ state, but emphasize that SV40‐transformed 3T3 cells do not show higher activity of the D‐glucose carrier than do actively growing 3T3 cells. Thus, enhanced glucose transport appears not to be a specific consequence of transformation, but a reflection of the active growth state of the cell.