Even though some studies did not indicate downregulations of glucose transporters in retinal capillary endothelial cells [34] or rat heart endothelial cells [35], vascular endothelial cells exposed to hyperglycaemia usually downregulate the rate of glucose transport by reducing GLUT1 and GLUT3 mRNAs and their protein expression. This evidence concerns the gene SLC2A1 and Hyperglycemia.