Determination of calcium, sodium, potassium and magnesium concentrations in human senile cataractous lenses

Cataractous lenses have been found to have a distribution of the intracellu lar ionic environment, the concentrations of potassium and magnesium decrea sing and the concentrations of sodium and calcium increasing relative to th e cytosol of most cells. This arises as a result of changes to lens membran e characteristics causing an increase in lens membrane permeability. These changes have been found to be initiated as a result of normal ageing of the human lens. In this study, total Ca2+, K+, Na+ and Mg2+ contents have been determined in human normal and cataractous lenses using atomic absorption and flame emission spectroscopy. The normal human lens Ca2+ is between 0.15 and 0.5 mu mol g(-1) fresh lens weight; in senile cataracts the value incr eased up to 9.31 mu mol g(-1) (p < 0.0001). The normal levels of Na+, Mg2and K+ are 20, 5.5 and 60 <mu>mol g(-1) respectively; these changed to 136. 10, 3.60 and 9.33 mu mol g(-1), respectively in cataractous senile human le nses (p < 0.002, p < 0.002 and p < 0.01). The remarkable differences in the se elements may play some role in cataractogenesis. Copyright (C) 2000 John Wiley & Sons, Ltd.