Photoinduction of cataracts in rat lens in vitro. Preventive effect of pyruvate

Intact rat lenses were incubated in riboflavin-containing Tyrode solution or medium-199, generating photochemically active species of oxygen and the oxidative stress measured in terms of the decrease in active accumulation of rubidium, and the fall in the levels of glutathione and ATP. Addition of pyruvate to the medium prevented the tissue against oxidative damage as evidenced by a greater accumulation of rubidium and higher levels of glutathione and ATP. Pyruvate was thus found to be effective against the toxicity of oxygen derivatives, particularly the hydrogen peroxide. In dark experiments also, conducted in glucose-free medium, the uptake of rubidium was substantially greater in the presence of pyruvate. The levels of ATP were also higher. These results, therefore, suggest that this ketoacid is beneficial to the tissue through its ability to decompose H2O2 as well through providing a metabolic support. The development of in vitro cataract under the photochemical effects of riboflavin and oxygen was also effectively thwarted by pyruvate. The results are thus potentially useful from the point of view of developing pyruvate and similar compounds as effective anticataract agents.