Sorbitol production in the lens: a means of counteracting glucose-derived osmotic stress.
Heretofore, the intracellular accumulation of sorbitol has been associated exclusively with deleterious (cataractogenic) changes in the lens. This study demonstrates a beneficial role for the sorbitol pathway in the rabbit lens, namely that of counteracting extracellular, glucose-derived, osmotic stress with the intracellular production of osmotically active sorbitol. Large and sudden increases in the extracellular glucose concentration lead to dehydration of the lens, a response that can be diminished by intracellular sorbitol and fructose production. These results are discussed in light of the impact (beneficial/detrimental) of aldose reductase inhibitors on the lens. Sugar cataract formation appears to result from continuous, rather than cyclical, activity of a pathway which normally may have a protective function in the lens.
D000818:Animals; D002386:Cataract / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology*; D066298:In Vitro Techniques; D007908:Lens, Crystalline / Q000187:drug effects / Q000378:metabolism*; D009997:Osmotic Pressure; D011817:Rabbits; D013012:Sorbitol / Q000378:metabolism*
D013012:Sorbitol; D005947:Glucose