Glucose is conveed to sorbitol by
In lens, the enzyme aldose reductase reduces monosaccharides to corresponding sugar alcohols; glucose to sorbitol and galactose to galactitol. POLYOL PATHWAY OF GLUCOSE - Sorbitol is very poorly absorbed from intestine. It involves the reduction of glucose by aldose reductase to sorbitol, which can then be oxidized to fructose. This would amount to the interconversion of glucose to fructose. Glucose when conveed to sorbitol, cannot diffuse out of the cell easily and gets trapped there. Sorbitol is normally present in lens of eyes. But in diabetes mellitus, when glucose level is high, the sorbitol concentration also increases in the lens. This leads to osmotic damage of the tissue and development of cataract. Galactitol also causes cataract. REF: DM VASUDEVAN TEXTBOOK OF BIOCHEMISTRY, SIXTH EDITION, PG.NO.,119,588.
Aldolase B
Aldose reductase
Sorbitol Dehydrogenase
UDP galactose 4 epimerase
Metabolism of carbohydrate