In the polyol pathway glucose is reduced by aldose reductase to sorbitol. Sorbitol dehydrogenase can then oxidize sorbitol to fructose.
Aldose reductase has a wide specificity
- Aldose Reductase
/product="aldo-keto reductase family 1 member A1"
Brenda Human liver 6-pyruvoyl tetrahydropterin reductase is biochemically and immunologically indistinguishable from aldose reductase
Aldose reductase has a high Km for both Glucose and NADPH
Flow trough this pathway lead to low NADPH/NADP and high NADH/NAD ratio