Glucose transport correlates with GLUT2 abundance in rat liver during altered thyroid status

Glucose transport activity ([3H]D-glucose uptake) in liver sinusoidal membrane vesicles (SMVs) from hyperthyroid rats was significantly higher than that from euthyroid controls (2.1-times increase in V(max) with K(m) unchanged at approximately 18 mM), associated with increased GLUT2 expression. In contrast, glucose transport V(max) into SMVs from hypothyroid rats was reduced to 0.75-times that of euthyroid controls, associated with a reduced GLUT2 abundance. GLUT1 expression in SMVs was unaffected by changes in thyroid status. GLUT2, but not GLUT1 abundance on the blood-facing membrane of liver cells is sensitive to changes in thyroid status and these changes in transporter expression directly correlate (r = 0.96) with altered glucose transport activity.