Objective To study the effects of high glucose and transforming growth factor β1 (TGF β1) on the expression and function of glucose transporter 1 (GLUT1) in mouse mesangial cells Methods Cultured mouse mesangial cells were used The expression of GLUT1 mRNA was detected by Northern Blot; glucose uptake and its kinetics were determined with a 2 Deoxy [ 3H] D glucose uptake assay Results Mesangial cells exposed to enriched glucose medium (20?mmol/L) for 72 hours demonstrated a decrease in both GLUT1 mRNA and V max for uptake of the glucose analog, 2 deoxy D glucose (2DOG), as compared to mesangial cells cultured in physiologic glucose concentrations(5 5?mmol/L) In contrast, hypertonic mannitol had no effect on GLUT1 mRNA levels TGF β1 treatment for 10 hours stimulated 2DOG uptake, both in 5 5?mmol/L and 20?mmol/L glucose medium, by approximately 4 28 fold in a dose dependent manner (2?ng/ml maximum) Kinetic analysis of 2DOG uptake revealed an increase in V max and a decrease in K m in the presence of TGF β1 TGF β1 also up regulated the expression of GLUT1 mRNA in mesangial cells The addition of anti TGF β neutralizing antibody (30?μg/ml) in mesangial cells cultured in enriched glucose medium (20?mmol/L) led to a 40% decrease in 2DOG uptake Conclusions The expression of GLUT1 can be suppressed by exposure of mesangial cells to high glucose medium, which may serve as a protective mechanism against possible adverse effects of excessive glucose flux into cells TGF β1 stimulates glucose uptake by enhancing the expression and function of GLUT1 in mesangial cells This effect is independent of the glucose milieu in the cultured medium Objective To study the effects of high glucose and transforming growth factor β1 (TGF β1) on the expression and function of glucose transporter 1 (GLUT1) in mouse mesangial cells Methods Cultured mouse mesangial cells were used The expression of GLUT1 mRNA was detected by Northern Blot ; glucose uptake and its kinetics were determined with a 2 Deoxy [3H] D glucose uptake assay Results Mesangial cells exposed to enriched glucose medium (20? mmol / L) for 72 hours demonstrated a decrease in both GLUT1 mRNA and V max for uptake of The glucose analog, 2 deoxy D glucose (2DOG), as compared to mesangial cells cultured in physiologic glucose concentrations (5 5 mmol / L) In contrast, hypertonic mannitol had no effect on GLUT1 mRNA levels TGF β1 treatment for 10 hours stimulated 2DOG uptake, both in 5? mmol / L and 20? mmol / L glucose medium, by about 4 28 fold in a dose dependent manner (2? ng / ml maximum) Kinetic analysis of 2DOG uptake revealed an i ncrease in V max and a decrease in K m in the presence of TGF β1 TGF β1 also up regulated the expression of GLUT1 mRNA in mesangial cells The addition of anti TGF β neutralizing antibody (30 μg / ml) in mesangial cells cultured in enriched glucose medium (20? mmol / L) led to a 40% decrease in 2DOG uptake Conclusions The expression of GLUT1 can be suppressed by exposure of mesangial cells to high glucose medium, which may serve as a protective mechanism against possible adverse effects of excessive glucose flux into cells TGF β1 stimulated glucose uptake by enhancing the expression and function of GLUT1 in mesangial cells This effect is independent of the glucose milieu in the cultured medium