[Metabolic changes of aldose and phosphorus metabolites in incubated rabbit lenses--effects of aldose reductase inhibitor].

We measured the metabolic changes in aldose and phosphorus metabolites in rabbit lenses incubated with tissue culture medium 199 (TCM 199) containing 20 mM glucose-1-13C, using 13C, 31P-NMR Spectroscopy (13C, 31P-MRS). Then we investigated the effects of aldose reductase inhibitor (ARI) on those metabolic changes, using the same method. In the incubated rabbit lenses, rapid increases were recognized in sorbitol, sorbitol-3-phosphate, and alpha-glycerophosphate. The levels of glucose, lactate, and adenosin triphosphate (ATP) did not change significantly. Once ARI was added, the levels of sorbitol and sorbitol-3-phosphate were reduced immediately, but the reduction of alpha-glycerophosphate needed some time after the addition of ARI. On the other hand, the levels of lactate increased approximately two-fold, and the levels of glucose and ATP did not change significantly. Considered with our other observations on the metabolic changes in alloxan induced diabetic rabbit lenses, and in rabbit lenses incubated with high concentrations (5-40 mM) of glucose-TCM 199 or 20 mM galactose-TCM 199, these results suggest that aldose reductase not only activates the polyol pathway but also controls the Embden-Meyerhof pathway, energetic metabolic changes, or phospholipid-associated metabolic changes.