Deoxyglucose transport of uninfected, murine sarcoma virus-transformed, and murine leukemia virus-infected mouse cells |
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Authors: | P G Plagemann |
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Abstract: | The initial rates of deoxy-D-glucose transport by cultures of growing and density-inhibited mouse embryo cells and lines of mouse cells transformed spontaneously or after infection by murine leukemia virus or murine sarcoma virus were investigated as a function of the deoxyglucose concentration. The apparent Km for deoxyglucose transport was about the same for all types of cells (1–2 mM). The Vmax of secondary cultures of mouse embryo cells decreased from 6 nmoles/106 cells/minute for sparse cultures to less than 1 nmole/106 cells/minute for density-inhibited cultures. The Vmax was about the same whether estimated in monolayer culture or in suspensions of cells dispersed by treatment with trypsin. The Vmax for deoxyglucose transport by the established cells, whether transformed spontaneously or by virus infection, was 4 to 25 times higher than that for density-inhibited mouse embryo cells and was independent of the cell density of the cultures. Deoxyglucose transport was competitively inhibited by Cytochalasin B, Persantin, glucose and 3-O-methyl-D-glucose and the apparent Ki values of inhibition were similar for the mouse embryo cells and the various cell lines. Similarly, the sensitivity of the glucose transport systems to inactivation by p-chloromercuribenzoate was about the same for all types of cells. The results suggest that the glucose transport system of the normal mouse embryo cells and the cells of the various established lines is qualitatively the same, but that the number of functional transport sites differs for the various cell lines and decreases markedly in mouse embryo cells with an increase in cell density of the cultures. |
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