Histopathology and ultrastructure of rabbit lenses exposed 'in vitro' to lysophosphatidylcholine (LPC)

Permeability changes which take place in the lens in the course of uveitis are probably due to 'Lens Permeability Factors' present in the inflammatory aqueous. One of these 'factors', lysophosphatidyl-choline (LPC), has been shown to damage the lens in vitro: a leakage of Rb(86) and proteins, and an increase of Na(+) and water content indicate a dose-related membrane lytic effect. Damaging levels of LPC (up to 10μg/ml of aqueous humor) were found in the anterior chamber of inflamed eyes in the course of experimental uveitis in rabbits, and also in humans during uveitis. This report deals with an ultrastructural investigation on the damaging effect of different concentrations of LPC on rabbit lenses in culture. Concentrations of LPC higher than 12μg/ml caused signs of degeneration immediately below the capsule. Scanning electron microscopy revealed grossly enlarged lens fibers, globular structures of different size and widespread water vacuoles. Transmission electron microscopy showed inter- and intracellular changes in the epithelium and the outer cortex, swollen lens epithelial cells, fiber cells separation, vacuoles, and areas of decreased electron density. The overall structure of the lens fibers in the inner cortex and in the nucleus was always intact.