Modeling cortical cataractogenesis. V. Steroid cataracts induced by solumedrol partially prevented by vitamin E in vitro

Rat lenses incubated in tissue culture medium (M 199) maintain their transparency for a long period of time. The soluble corticosteroid, solumedrol (methyl prednisolone sodium succinate) was added to the medium, at concentrations including the range expected during rejection episodes following organ transplantation (3.8 X 10(-9) M-3.8 X 10(-6) M). At the lowest level used (3.8 X 10(-9) M), five lenses of 12 became opaque following a 48 hr incubation, while at higher concentrations of solumedrol almost all lenses developed opacities. Addition of vitamin E to the medium resulted in partial prevention of the cataract as judged by the smaller proportion of lenses becoming opaque. Examination of the lenses by scanning and transmission electron microscopy (SEM and TEM, respectively), indicated that in untreated lenses the initial location of the cataract is at the anterior pole of the lens where a deepening area of degeneration formed, followed by a uniform subcapsular layer of degeneration spreading over the remainder of the lens. Damage at this location is not typical of most in vitro cortical cataracts. In the presence of vitamin E the extent of damage was less, involving, initially, an equatorial wedge of globular degeneration and spreading anteriorly and posteriorly in a thinner subcapsular layer. This type of damage was more typical of that seen previously for cataracts induced by cytochalasin D, elevated glucose and hygromycin B.