Comparative study on aging, UV treatment, and radiation on cataract formation

Abstract

Four randomized groups of male mice F1 (C57Black/CBA) were investigated: a) UV-irraidated (UV-A, 15 min daily during 9 months, dose 5.6 + 1.2 W/m2), b) gamma-rays irradiated (2 Gy), single, c) influence for combination of UV- and gamma-rays treatment, d) aging. The lens opacities were measured on 7th and 10th month. The expert method based on six grade scale was used for cataract measure. On 7th month the median of lens opacities were Aging group = 0; UV-irradiated group = 2.5; gamma-irradiated group = 4.75; gamma- and UV-irradiated group = 6.0. The difference between all groups was significant (p < 0.004, Kruskall-Wallis ANOVA test). The Conover post hock test has shown the significant difference for all comparison pairs (p < 0.002) with the exception of UV-irradiated group, gamma-irradiated group, gamma- and UV-irradiated group. On 10th month the lens opacities were strongly increased: Aging group = 2.5; UV-irradiated group = 5.0; gamma-irradiated group = 6.5; gamma- and UV-irradiated group = 7.5 (median). The difference between groups was significant (p < 0.0001, Kruskall-Wallis ANOVA test). The Conover post hock test has shown the significant difference for all comparison pairs (p <0.003) with the exception ofthe UV-irradiated group and gamma-irradiated group. The formation of the specific lens opacities for any group was not found. Morphology and protein composition have been investigated on 10th month. The results of morphological changes study show destructive and degenerative impairments of capsule, epithelium cells and lens fibers. However, no specific changes related to some particular actions have been found. In addition, there were no specific changes of protein composition of both water-soluble and water-insoluble fractions estimated with Differential Gel Electrophoresis technique. Obtained data mean that aging, UV-treatment, and gamma-radiation causes the similar changes of lens. It was supposed that UV-treatment or/and gamma-radiation act as an aging factor on the lens.