Stimulation of sugar uptake in cultured fibroblasts by epidermal growth factor (EGF) and EGF‐binding arginine esterase

Publisher Website
Google Scholar
Abstract
Mouse epidermal growth factor causes a rapid increase in 2‐deoxyglucose uptake in stationary phase mouse (3T3) cells or human fibroblasts. Maximum effect is approximately two fold over control levels for 3T3 cells and about 50% over controls for human fibroblasts. Maximum effect on 3T3 cells is seen about two hours after addition of 10 ng/ml EGF to the culture medium. Stimulation is easily measurable within the first fifteen minutes after addition of the hormone and may be detected at hormone concentrations as low as 0.1 ng/ml. The EGF‐binding arginine esterase found associated with EGF in the mouse submaxillary gland causes an enhancement of the EGF effect. In serum‐free medium, the EGF effect is still readily observed, but no enhancement by the esterase is seen. SV40 virus‐transformed 3T3 cells show no effect on deoxy‐glucose uptake after addition of 10 ng/ml EGF to the culture medium, but a response may be demonstrated after these cells are incubated for 12 hours or more in serumless medium. EGF stimulates transport of 3‐0‐methylglucose in stationary phase 3T3 and human fibroblasts but no EGF stimulation of α‐amino‐isobutyrate uptake in 3T3 cells is seen under conditions in which EGF clearly stimulates sugar uptake. Ammonium chloride, which is reported to inhibit intracellular degradation of human EGF by human fibroblasts, does not diminish the EGF effect on deoxyglucose uptake in human fibroblasts.