[Ascorbic acid. Cytotoxic effect on cultivated bovine lens epithelium cells]

Ascorbic acid is one of the main components (1.16 mM/l) of the aqueous humor. The molarity of this molecule is 25 times higher than in the plasma of the cow, man or horse. Now the question arises as to which function ascorbic acid has in this extremely high concentration referring to the proliferation of the lens epithelial cells. Thus, the effect of ascorbic acid was investigated upon bovine lens epithelial cells (BLEC) in the range of 0-3 mM/l. These cells were cultivated under various culture conditions (serum-free, serum-containing, aqueous-humor-containing medium) and also incubated with such mitogens as retinal extract (RE), crude endothelial cell growth factor (cECGF), basic fibroblast growth factor (bFGF) or with calcium. In each culture condition 1 mM/l ascorbic acid caused remarkable inhibition of the proliferation of BLEC. Higher concentrations (> 1.5 mM/l) revealed cytotoxic effects. These effects were independent of small variations in the pH value caused by ascorbic acid. In addition, the effect of 2 mM/l ascorbic acid in combination with catalase in a concentration of 500 Um/ml and 1000 Um/ml, respectively, was investigated. It could be shown that catalase is capable of preventing the cytotoxic effect of ascorbic acid. These results show the inhibitory effect of ascorbic acid in its physiological concentration in the proliferation of BLEC.