A MILD PROGRESSION TYPE OF NAPHTHALENE-INDUCED CATARACT IN BROWN-NORWAY RATS

Naphthalene-induced rat cataract is a useful experimental cataract - h owever, because of its short survival period, studies using this model have been for limited purposes. Based on the consideration that the s hort survival might be caused by systemic toxicity of an overdose of n aphthalene administration (1 g/kg body weight every other day), the au thors successfully established a naphthalene-induced cataract with mil d progression in Brown-Norway rats. The naphthalene administration pro posed is to initially administer 0.5 g/kg and after a 1-week interval 1 g/kg of 10% naphthalene once or twice a week through a stomach tube. While the type of lens opacification induced in the two groups admini stered once and twice a week, respectively, was the same as that seen by the previous administration method, the progression of lens opacifi cation seen in the groups showed a dose-dependent increase. The surviv al rate in the rats given naphthalene every other day according to the old method was 50% at the 6th week and 0% at the 9th week. Survival o f the two new groups was 70 and 60% at the 30th week, respectively. Th is new type of naphthalene-induced rat cataract should be a suitable m odel for long-term observations.