Inhibition of lens opacification during the early stages of cataract formation.

PURPOSE: To characterize the time period during cataract formation in which administration of pantethine inhibits lens cell opacification in the selenite model for cataract.
METHODS: Pantethine was administered to neonatal rat pups at selected time points from -0.5 to 17 hours with respect to injection of selenite at time = 0. The injection dose of pantethine was 820 mg/kg (1.5 mmol/kg) diluted in water at 410 mg/ml concentration. The injection dose of selenite was 3.28 mg/kg (19 mumol/kg) diluted in saline at 1.8 mg/ml concentration. Opacification was observed using a slit lamp microscope at selected time points over a 14-day period. Cataracts were staged using a classification of opacity from 0 (normal) to 6 (mature).
RESULTS: The effect of pantethine was characterized by three different time periods: administration -0.5 to 6 hours with respect to selenite injection provided highly significant protection, P < 0.001; administration 8 hours after selenite provided significant protection, P < 0.005; administration 10 to 17 hours after selenite was not protective.
CONCLUSIONS: The metabolite pantethine inhibited lens opacification during cataract formation in the selenite model. Even when pantethine was injected several hours after the administration of selenite, opacification was inhibited. Advanced stages of opacification were unresponsive to the administration of pantethine. The inhibitory effect of pantethine was statistically significant when administered during the earliest stage of opacification in the selenite model for cataract.