Sugar transport in chick embryo cardiac cells in culture: analysis by countertransport, relationship to phosphorylation and effect of glucose starvation.
Embryonic chick heart cells in culture transport 2-deoxy-D-glucose and 3-O-methyl-D-glucose very rapidly. By direct measurements of uptake, it was not possible to estimate accurately transport rates, nor, with 2-deoxyglucose, to discriminate clearly between its transport and phosphorylation. In contrast, the technique of countertransport made it possible to determine precisely initial transport velocity and to make the following observations: (1) phosphorylation, and not transport, is rate-limiting in 2-deoxyglucose uptake; (2) hexose transport is stimulated 5-fold by removal of glucose from culture medium; and (3) this stimulation is followed by an increase in phosphorylation, but the effect is much less pronounced (2-fold stimulation only). In conclusion, the adaptative regulation of glucose transport described in many fibroblast cell lines exists also in cardiac cells.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D003847:Deoxyglucose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D006601:Hexoses / Q000378:metabolism*; D008757:Methylglucosides / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D010766:Phosphorylation
D006601:Hexoses; D008757:Methylglucosides; D003847:Deoxyglucose; D005947:Glucose