The effect of pantethine and ultraviolet-B radiation on the development oflenticular opacity in the emory mouse

Purpose. Few studies have examined the impact of long-term treatments or ex posures on the development of cataract in maturity-onset animal models. We studied the effect of treatment with D-pantethine and exposure to ultraviol et-B (UVB) radiation on the development of lenticular opacity in the Emery mouse. Methods. A total of 164 Emery mice were randomized by litter at weaning to exposure to WE light at 12 mJ/cm(2) for 6 hr/day (UV) or usual room light ( A), and within litter, were further randomized to bi-weekly intra-peritonea l injections of 0.8 g/kg pantethine (T) or no treatment (C). Retro illumina tion lens photos were taken at 2, 4, 6, 8, and 10 months after weaning, and graded in masked fashion. The animals were sacrificed at 10 months and the lenses analyzed for total pantethine and total cysteamine. Results. Lens pantethine and cysteamine levels were significantly (P < 0.00 1) higher for the T as compared to C litters. Mean cataract grade increased monotonically over time for all four groups. Unadjusted mean grade for the AT group at 8 (1.32) and 10 (1.86) months appeared lower than for the othe r groups (AC: 2.17, 2.39; UVC: 1.77, 2.40; UVT: 1.88, 2.37). However, the m ean grade for the pantethine-treated litters did not differ significantly f rom the untreated litters except at 2 months (when untreated litters had si gnificantly lower grades), when adjusting for UV treatment, gender and litt er effect. No significant difference in cataract score existed between UV-e xposed and ambient litters. Mortality was higher among pantethine-treated ( hazard ratio = 1.8, p = 0.05) and UV-exposed animals (hazard ratio = 1.8, p = 0.03) than among the untreated and unexposed litters. Conclusion. Significantly increased lens levels of pantethine are achieved with long-term intra-peritoneal dosing. The impact of pantethine on the pro gression of lenticular opacity in the Emery mouse is less than has been rep orted in other models. This level of chronic UVB exposure appeared to have no effect on the development of cataract in this model.