Comparison of aldose reductase inhibitors by determination of IC50 with bovine and rat lens extracts.

The inhibition constants of several aldose reductase inhibitors were determined using water-soluble extracts of bovine and rat lenses. The most potent inhibitor was the Alcon compound AL-1576; the inhibitory effects of AL-1567 and Sorbinil were about equal, but both were less effective than AL-1576, and the least effective inhibitor was the calcium antagonist verapamil. There was no general difference between inhibition constants for the inhibitors in question between bovine or rat extracts. Age of bovine lenses has no effect on the IC50 of the investigated aldose reductase inhibitor compounds.