Lens Membrane Properties Following Hydrogen Peroxide Exposure

Rabbit lenses exposed to 0.5 mM hydrogen peroxide for 1 h and then incubated for an additional 19 h demonstrated small yet significant changes in electrolyte balance. Active cation pumping by the lens, as determined by 86Rb uptake studies, was partially impaired following 1 h hydrogen peroxide exposure; the cation pump further deteriorated during the subsequent 19-hour incubation. Passive membrane permeability of the lens, measured by 86Rb efflux, was elevated following 1 h hydrogen peroxide but no further increase in leakiness was observed during the subsequent 19-hour incubation. These findings suggest that even relatively brief exposure to oxidative damage initiates a chain of events from which the lens is unable to recover.