Glucose metabolism by human cataracts in culture.
Metabolism in human senile cataracts has been studied using uniformly labeled [14C]glucose. Intracapsularly extracted lenses were cultured in TC-199 media with a glucose concentration of 5.5 mM. Results show that lactate production accounts for 97% of the glucose metabolized. Under these standard incubation conditions there is negligible accumulation of alpha-glycerol phosphate, glucose-6-phosphate, and sorbitol. The rate of lactate production was found to be relatively uniform over a range of cataract severities which were determined from the CCRG classification. The effects of several perturbants in the medium were measured. An ATP concentration of 3 mM was found to inhibit lactate production. Labeled glucose-6-phosphate in the medium was found to produce lactate at a rate approximately one half that of glucose. Elevated glucose concentration resulted in a slight decrease in lactate production and, in some lenses, production of a small amount of sorbitol. Overall, the glycolytic pathway appears to be functioning normally and without regard for cortical and nuclear opacification.
D000255:Adenosine Triphosphate / Q000494:pharmacology; D002386:Cataract / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005947:Glucose / Q000378:metabolism*; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000378:metabolism; D005994:Glycerophosphates / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007773:Lactates / Q000378:metabolism
D005958:Glucosephosphates; D005994:Glycerophosphates; D007773:Lactates; D019298:Glucose-6-Phosphate; D000255:Adenosine Triphosphate; D005947:Glucose