PREVENTION OF INTRACELLULAR OXIDATIVE STRESS TO LENS BY PYRUVATE AND ITS ESTER

Pyruvate is a well-known scavenger of hydrogen peroxide (H2O2). Ln add ition, it scavenges superoxide radical (O-2(.-)). However, evidence on its intracellular antioxidant function is meager at present Hence, we have examined the effectiveness of this metabolite and its ethyl este r against intracellular oxidative damage to the lens under organ cultu re. Menadione, a redoxcycling quinone, was used to generate the reacti ve oxygen species (ROS). It was found to inhibit lens metabolism as ev idenced by a decrease of Am. Additionally, tissue oxidation was appare nt by loss of glutathione (GSH), and increase in the level of oxidized glutathione (GSSG), coupled with increase of the urea soluble protein s (water insoluble). The overall physiological damage was apparent by the inhibition of the Na+-K+-ATPase dependent cation pump, as evidence d by a decreased rubidium transport. These deleterious effects were at tenuated by pyruvate and ethyl-pyruvate. The later was found to be mor e effective.