title: Effects of free radicals on cytosolic creatine kinase activities and protection by antioxidant enzymes and sulfhydryl compounds.
abstract: The main purpose of this study was to investigate the effect of free radicals and experimental diabetes on cytosolic creatine kinase activity in rat heart, muscle and brain. Hydrogen peroxide decreased creatine kinase activity in a dose dependent manner which was reversed by catalase. Xanthine/xanthine oxidase, which produces superoxide anion, lowered the creatine kinase activity in the same manner whose effect was protected by superoxide dismutase. N-acetylcysteine and dithiothreitol also significantly ameliorated the effect of Xanthine/xanthine oxidase and hydrogen peroxide. Experimental diabetes of twenty-one days (induced by alloxan), also caused a similar decrease in the activity of creatine kinase. This led us to the conclusion that the decrease in creatine kinase activity during diabetes could be due to the production of reactive oxygen species. The free radical effect could be on the sulfhydryl groups of the enzyme at the active sites, since addition of sulfhydryl groups like N-acetylcysteine and dithiothreitol showed a significant reversal effect.
authors.affiliation: Hormone and Drug Research Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
authors.forename: S
authors.initials: S
authors.lastname: Genet
authors.forename: R K
authors.initials: RK
authors.lastname: Kale
authors.forename: N Z
authors.initials: NZ
authors.lastname: Baquer
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001786:Blood Glucose / Q000032:analysis; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D002374:Catalase / Q000494:pharmacology; D003402:Creatine Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology; D004229:Dithiothreitol / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology; D005609:Free Radicals / Q000378:metabolism*; D006321:Heart / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007328:Insulin / Q000008:administration & dosage / Q000097:blood; D018482:Muscle, Skeletal / Q000187:drug effects / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar; D013438:Sulfhydryl Compounds / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000494:pharmacology; D019820:Xanthine / Q000494:pharmacology; D014969:Xanthine Oxidase / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D001786:Blood Glucose; D016166:Free Radical Scavengers; D005609:Free Radicals; D007328:Insulin; D013438:Sulfhydryl Compounds; D019820:Xanthine; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D003402:Creatine Kinase; D004229:Dithiothreitol; D000111:Acetylcysteine