title: Exercise training alters kinetics of antioxidant enzymes in rat tissues.
abstract: Michaelis-Menten constant (Km) and maximum velocity (Vmax) of catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) in various tissues of exercise-trained old rats were compared with the age matched sedentary control. Exercise training increased the maximum velocity (Vmax) for CAT in the brain (350%), liver (33%), lung (34%), muscle (25%) and testes (21%); for GSH-Px (using t-butyl hydroperoxide as a substrate) in the liver (22%), lung (25%), and testes (52%); for GSH-Px (using GSH as a cosubstrate) in the brain (64%) and liver (100%), and for GR in testes (50%). This increase in Vmax indicates the potential activation of these enzymes in the specific tissues. Exercise training differentially altered the affinities of enzyme (Km) for CAT, GSH-Px and GR to their substrates. These studies suggest that exercise training provided a beneficial role by activation of antioxidant enzymes in specific tissues of aged rats. Thus, exercise training aids in coping with oxidative stress in old age.
authors.affiliation: Department of Pharmacology, Southern Illinois University School of Medicine, Springfield 62794-1222, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Somani
authors.forename: K
authors.initials: K
authors.lastname: Husain
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001921:Brain / Q000201:enzymology; D002374:Catalase / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000378:metabolism*; D005980:Glutathione Reductase / Q000378:metabolism*; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008168:Lung / Q000201:enzymology; D008297:Male; D009132:Muscles / Q000201:enzymology; D009928:Organ Specificity; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D013737:Testis / Q000201:enzymology
chemical_list: D000975:Antioxidants; D002374:Catalase; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase