Prevention of intracellular oxidative stress to lens by pyruvate and its ester.
Pyruvate is a well-known scavenger of hydrogen peroxide (H2O2). In addition, it scavenges superoxide radical (O2.-). However, evidence on its intracellular antioxidant function is meager at present. Hence, we have examined the effectiveness of this metabolite and its ethyl ester against intracellular oxidative damage to the lens under organ culture. Menadione, a redoxcycling quinone, was used to generate the reactive oxygen species (ROS). It was found to inhibit lens metabolism as evidenced by a decrease of ATP. Additionally, tissue oxidation was apparent by loss of glutathione (GSH), and increase in the level of oxidized glutathione (GSSG), coupled with increase of the urea soluble proteins (water insoluble). The overall physiological damage was apparent by the inhibition of the Na+-K+-ATPase dependent cation pump, as evidenced by a decreased rubidium transport. These deleterious effects were attenuated by pyruvate and ethyl-pyruvate. The later was found to be more effective.
Varma
S D
SD
Department of Ophthalmology, University of Maryland School of Medicine, Baltimore 21201, USA.
Devamanoharan
P S
PS
Ali
A H
AH
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects; D016166:Free Radical Scavengers / Q000494:pharmacology*; D017136:Ion Transport / Q000187:drug effects; D007908:Lens, Crystalline / Q000187:drug effects* / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects; D011773:Pyruvates / Q000494:pharmacology*; D019289:Pyruvic Acid / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D012413:Rubidium / Q000378:metabolism; D014812:Vitamin K / Q000494:pharmacology / Q000633:toxicity
D000975:Antioxidants; D016166:Free Radical Scavengers; D011773:Pyruvates; D017382:Reactive Oxygen Species; C046522:ethyl pyruvate; D014812:Vitamin K; D019289:Pyruvic Acid; D000255:Adenosine Triphosphate; D012413:Rubidium