Fig. 2

The Polyol pathway, involving two subsequent reactions regulated by AKR1B1 and SORD can convert glucose into fructose. Alternatively, GLUT5 receptor, encoded by SLC2A5, allows the entry of fructose into the cell. Fructolysis is able to avoid two crucial regulatory steps: Hexokinase (HK) is inhibited by its product (G-6-P) while phosphofructokinase (PFK) is inhibited by the ATP steady state levels