Inhibition of aldose reductase from human retina

Aldose reductase was prepared from a pool of 21 male and 16 female human retinas by ammonium sulphate fractionation (40–75% saturation) and chromatography on DEAE-Sephacel and Matrex-OA. The overall purification was 132-fold with 50% recovery of enzyme activity.The concentrations of the aldose reductase inhibitors Sorbinil, Statil and M79175 required to give 50% inhibition (IC50 value) of enzyme activity with the model substrate 4-nitrobenzaldehyde (4NB) were 3.4μM, 2.3μM and 0.22μM respectively. This indicated that M79175 was the most effective inhibitor tested of aldose reductase with 4NB in vitro. These inhibitors were more effective when tested against aldose reductase activity with glucose, the substrate which might play a role in the pathogenesis of diabetic complications. Sorbinil gave an IC50 (glucose) of 0.40μM; M79175 and Statil were more effective. At an inhibitor concentration of 0.1μM the %-inhibitions observed were: Sorbinil 20% M79175 55%, Statil 76%. Thus Statil was the most potent compoun...