Effects of Gender and Gonad Status on N-Methyl-N-nitrosourea-induced Cataractogenesis and Retinopathy in Lewis Rats

Abstract

Background: The effects of differences in gender and gonadal status on the occurrence of N-methyl-N-nitrosourea (MNU)-induced cataract and retinopathy were studied using ovary-intact, ovariectomized, testis-intact and testectomized Lewis rats. Materials and Methods: Castration was performed at 36 days of age, 50 mg/kg MNU was administered intraperitoneally at 50 days of age, and lens and retinal changes were evaluated at 260 days of age (210 days after MNU injection). Results: Although there was little difference in the incidence of cataract and retinopathy among the groups, ovary-intact rats had a significantly higher cataract index and retinal damage ratio (both are indicators of disease severity) than ovariectomized rats and testis-intact rats, respectively. However, the cataract index and retinal damage ratio did not correlate with the serum 17β-estradiol and progesterone levels, respectively. Conclusion: The presence of ovaries and female gender appear to be associated with greater severity of cataracts and retinopathy, respectively, but the severity of these diseases did not correlate with the serum hormone levels.