Effects of Vanadate on Glucose Metabolism in the Lens of Rats with Streptozotocin-Induced Diabetes
Ketohexokinase and Aldolase Activities

Kazuhiko Adachi, Minoru Endo, Masao Nagata and Akihiko Tamai

Department of Ophthalmology, Faculty of Medicine, Tottori University, Yonago 683, Japan

The effects of vanadate, an oxidized form of vanadium, on glucose metabolism in the lens of diabetic rats were studied. Five-week-old male Sprague-Dawley rats were rendand diabetic with intraperitoneal injection of streptozotocin (50 mg/kg). One week later, the diabetic rats were given 0.2 g/L NaV0₃-5g/L NaCl solution in drinking water ad libitum for 2 weeks and the biochemical parameters in their lenses were determined. Blood glucose levels significantly decreased in the vanadate-treated diabetic rats (diabetic, vanadate-treated group: DV group), compared with the diabetic rats given no vanadate (diabetic, control group: D group). In the DV group, a significant decrease was observed in lens fructose content compared with the D group. Lens ketohexokinase activity tended to be higher and lens aldolase activity was significantly higher in the DV group than in the D group. These results indicate that vanadate accelerates the metabolic reaction from the sorbitol pathway to glycolysis.

Key words: aldolase activity, diabetic rat lens, fructose, ketohexokinase activity, vanadate

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