Age-related changes in the activity of antioxidant and redox enzymes in rats.
Cellular defense system, including glutathione, glutathione-related enzymes, and antioxidant and redox enzymes, may play crucial roles in the aging of aerobic organisms. To understand the physiological roles of these factors in the aging process, their levels were compared in the livers and brains of 5-week- and 9-month-old rats. GST activity was higher in livers and brains of 9-month-old rats than in those of 5-week-old rats, and brain catalase activity was about 2-fold higher. However, it was unchanged in the livers of the 9-month-old rats. gamma-Glutamylcysteine synthetase activity was about 2-fold higher in the brains of the older rats but again not in their livers. In contrast glutathione synthetase activity appeared to be lower in the livers of the older rats while GSH content did not change with age in livers and brains. Glutathione peroxidase activity was higher in 9-month-old rat brains, but lower in 9-month-old rat livers, while superoxide dismutase activity was higher in both tissues in the older rats. The activities of two redox enzymes, thiol-transferase and thioredoxin reductase, did not change with age, nor did that of glutathione reductase. These results indicate that levels of different cellular defense systems vary with age in an irregular manner.
Kim
Hong-Gyum
HG
Division of Life Sciences, Kangwon National University, Chuncheon 200-701, Korea.
Hong
Sung-Min
SM
Kim
Su-Jung
SJ
Park
Hey-Jung
HJ
Jung
Haeng-Im
HI
Lee
Yuk-Young
YY
Moon
Jeong-Su
JS
Lim
Hye-Won
HW
Park
Eun-Hee
EH
Lim
Chang-Jin
CJ
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001921:Brain / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D010084:Oxidation-Reduction; D051381:Rats; D017207:Rats, Sprague-Dawley
D000975:Antioxidants; D005982:Glutathione Transferase; D005978:Glutathione