Hexose transport and phosphorylation by Novikoff rat hepatoma cells as function of extracellular pH.
The effect of extracellular pH on hexose uptake by cultured Novikoff hepatoma cells has been examined with respect to four distinct parameters: i) the transport of 3-O-methyl-D-glucose, ii) the uptake of 2-deoxy-D-glucose by intact cells, iii) the phosphorylation of 2-deoxy-D-glucose in vitro by cell-free preparations, and iv) the intracellular pH as measured by 5,5'-dimethyl[2-14C]oxazolidine-2,4-dione. Transport per se was not affected by pH in the range of 6 to 8, while uptake of 2-deoxy-D-glucose increased with pH 2- to 3-fold over this range. The pH sensitivity of uptake can be explained on the basis of a change in hexokinase activity effective in situ. The pH dependence of hexokinase observed in vitro, however, was insufficient to account for that apparent in situ.
D000818:Animals; D001693:Biological Transport, Active; D003837:Deoxy Sugars / Q000378:metabolism*; D003847:Deoxyglucose / Q000378:metabolism*; D006593:Hexokinase / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D008757:Methylglucosides / Q000378:metabolism*; D008759:Methylglycosides / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats
D003837:Deoxy Sugars; D008757:Methylglucosides; D008759:Methylglycosides; D003847:Deoxyglucose; D006593:Hexokinase