Effect of D-glucose on L-arginine transport in HUVECs.

L-Arginine uptake (100 μmol/L) in HUVECs exposed (0–24 hours) to Krebs solution with increasing concentrations of D-glucose, or 5 mmol/L D-glucose + 20 mmol/L L-glucose or 20 mmol/L D-mannitol (see Methods). Kinetics of saturable L-arginine transport (0–1000 μmol/L L-arginine, 2 μCi/mL L-[3H]arginine, 1 minute, 37°C) in cells exposed (24 hours) to Krebs solution containing 5 or 25 mmol/L D-glucose with insulin (0.01–10 nmol/L) (8 hours), or 5 mmol/L D-glucose + 20 mmol/L L-glucose or 20 mmol/L D-mannitol (see Methods). Vmax/Km: maximal transport capacity, ppSE50: primary peak half-stimulatory D-glucose effect, spSE50: secondary peak half-stimulatory D-glucose effect, hCAT-1: human cationic amino acid transporter 1.—denotes not significant change.*P†PEffect of D-glucose on L-arginine transport in HUVECs.