Fig. 4

Effect of hypoxia and reoxygenation on the cell-surface expression of GLUT1. a HUVECs were cultured under normoxia or 3 h or 12 h hypoxia, as described in the Materials and Methods. The cells were labeled with a human anti-GLUT1 Alexa Fluor^® 488-conjugated antibody to detect cell-surface GLUT1. b Effect of re-oxygenation on the cell-surface expression of GLUT1. HUVECs were cultured under 12 h hypoxia or 12 h normoxia following 12 h hypoxia. GLUT1 at the cell surface was determined as described in a. (a, b) The histograms represent cell counts (Y-axis, linear scale) versus fluorescence intensity (X-axis, log scale). Fluorescence mean intensity obtained from the histograms was quantified and shown in bar graphs (right panels). Data are the mean ± SEM from 4 independent experiments. *P < 0.01, ^#P < 0.05 vs. normoxia control (Mann–Whitney test). ^$P < 0.01 vs. hypoxia (12 h) (Mann–Whitney test)