Effects of L-malate on mitochondrial oxidoreductases in liver of aged rats.
Accumulation of oxidative damage has been implicated to be a major causative factor in the decline in physiological functions that occur during the aging process. The mitochondrial respiratory chain is a powerful source of reactive oxygen species (ROS), considered as the pathogenic agent of many diseases and aging. L-malate, a tricarboxylic acid cycle intermediate, plays an important role in transporting NADH from cytosol to mitochondria for energy production. Previous studies in our laboratory reported L-malate as a free radical scavenger in aged rats. In the present study we focused on the effect of L-malate on the activities of electron transport chain in young and aged rats. We found that mitochondrial membrane potential (MMP) and the activities of succinate dehydrogenase, NADH-cytochrome c oxidoreductase and cytochrome c oxidase in liver of aged rats were significantly decreased when compared to young control rats. Supplementation of L-malate to aged rats for 30 days slightly increased MMP and improved the activities of NADH-dehydrogenase, NADH-cytochrome c oxidoreductase and cytochrome c oxidase in liver of aged rats when compared with aged control rats. In young rats, L-malate administration increased only the activity of NADH-dehydrogenase. Our result suggested that L-malate could improve the activities of electron transport chain enzymes in aged rats.
Guangdong Institute of Microbiology, Guangzhou, China. wuqp203@ yahoo.com.cn
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D000375:Aging / Q000378:metabolism*; D000818:Animals; D045222:Electron Transport Chain Complex Proteins / Q000378:metabolism; D008293:Malates / Q000008:administration & dosage*; D008297:Male; D008930:Mitochondria, Liver / Q000201:enzymology*; D010088:Oxidoreductases / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D045222:Electron Transport Chain Complex Proteins; D008293:Malates; D010088:Oxidoreductases