In Vitro Production of Steroid Cataract in Bovine Lens

Abstract

Fresh calf lesnses incubated in nutritive media containing dexamethasone phosphate or ouabain in concentrations ranging from 1 X 10(-4) M to 1 X 10(-8) M developed cortical opacification and showed significant inhibition of Na(+)-K(+) ATP'ase activity. Over a 3-day incubation period the decrease in Na+-K+ ATP'ase activity correlated well with the observed decrease in light transmission. The degree of enzyme inhibition and decrease in light transmission varied directly with the concentration of dexamethasone phosphate and ouabain, with significant changes observed at 'physiologic' and 'pharmacologic' concentrations of these agents. Lenses incubated for 4 days in dexamethasone phosphate or ouabain showed substantial increases in water content as well as an increase in Na+ and a decrease in K+ concentration. These data suggest that inhibition of the cation pump may play a significant role in the formation of steroid cataract in vitro.

Advances in pharmacological strategies for the prevention of cataract development

“…[12] Steroids cause an inhibition of the cation pump in the lens capsule the resulting electrolyte/water imbalance is responsible for cataract formation. [13]…”

Cell Adhesion Molecule Expression in Human Lens Epithelial Cells After Corticosteroid Exposure

“…Although the association between topical and systemic steroid use and increased occurrence of posterior subcapsular cataract (PSC) has been known since 1960 [ 1 ], the mechanism behind this type of lens opacification has yet not been elucidated. Over the years, several mechanisms such as osmotic failure [ 2 , 3 ], metabolic disturbances [ 3 ], protein adduct formation [ 3 - 6 ], conformational changes due to oxidative stress [ 3 , 6 - 8 ], and receptor mediated changes [ 3 , 6 , 8 - 11 ] have been proposed to account for PSC formation, but the results are inconclusive.…”

“…Studies have suggested that glucocorticoids exert their actions both directly on lens function as previously mentioned, as well as indirectly via the glucocorticoid receptor (GR) [ 2 , 4 , 7 , 8 , 10 , 11 , 21 - 23 ]. In the lens, the presence of a functional GR was discussed for long.…”