Regulation of glucose transporter-1 mRNA levels by high glucose. Quantitative real-time RT-PCR analysis of glucose transporter-1 (GLUT-1) mRNA levels in chondrocyte cultures exposed to 30 mM glucose (high glucose medium (HGM)) for 6, 12 or 24 hours or maintained in regular glucose medium (RGM). (a) Normal chondrocytes (n = 3). (b) Osteoarthritis chondrocytes (n = 3). Results expressed as the fold increase relative to the respective control cells maintained in RGM. Bars = mean ± standard deviation.