In vitro modification of bovine lens aldose reductase activity.

Bovine lens aldose reductase can be activated in crude extracts upon incubation at 37 degrees C at relatively high ionic strength. This phenomenon shows a seasonal occurrence, the enzyme being susceptible to activation only in lenses of animals sacrified in summer. Systems generating oxygen activated species induce the enzyme activation, whereas scavengers of "oxygen radicals" preserve the activated state of the enzyme. Glutathione and other thiol compounds appear to prevent the enzyme activation.