[Aging of lens epithelial cells and their possible effect on lens opacity (senile cataract)]

Proliferation capacity, synthesis of lens-specific proteins, DNA alterations after UV- and X-ray irradiation as well as their repair capacity have been investigated in tissue cultures with isolated lens epithelial cells of different species and different donor ages, respectively. The in-vitro life span of diploid lens epithelial cells is limited. It is correlated positively with the life expectancy and negatively correlated with the donor age of the investigated animals. The capacity to synthesize lens-specific proteins is lost in late cultures of lens epithelial cells. The capacity to repair UV- and X-ray-induced DNA alterations does not change during aging in vitro, however, it decreases to 75% in cultures derived from old donor animals (bovine). Together with the special growth pattern of the organ lens, the in-vitro results are discussed in order to point out a possible mechanism which might contribute to the development of age-dependent lens opacities. The system "lens epithelial cells in vitro" is considered as a well-suited model system to study age-dependent alterations in the organ lens.