Aldose reductase in early streptozotocin-induced diabetic rat lens.

The present study investigates the status of lens aldose reductase in the early streptozotocin-induced diabetic rat. Aldose reductase protein concentration, protein synthesis, and enzyme activity was assayed at 3 days and 14 days post-streptozotocin injection. Our results indicated that there was no significant difference between normal (control) and diabetic rat lenses in these parameters during the time frame of the study. Results from whole lens analysis were supported by results of the examination of the isolated capsule-epithelium layer of these lenses. It is concluded from this study that in the initial stage of the diabetic cataract model, increase in enzyme protein or activity does not play a significant role in cataractogenesis, but rather that the hyperglycemic condition in combination with existing enzyme levels is sufficient to cause the cataractogenic changes.