title: Are oxygen radicals implicated in the calcium paradox of the rat heart?
abstract: No reduction in creatine kinase (CK) release during standard Ca2+ paradox in the Langendorff-perfused rat heart was afforded by anoxic perfusion, nor by addition of the radical scavengers superoxide dismutase (150,000 U/L), catalase (150,000 U/L), mannitol (15 or 50 mM), dimethylthiourea (DMTU, 10 mM), the antioxidant vitamin E (0.25 or 0.75 mM), or the iron chelator desferrioxamine (0.8 mM). Even under mild Ca(2+)-paradox conditions, achieved by (a) reducing the duration of the Ca(2+)-free period, (b) increasing [Ca2+]0 during the "Ca(2+)-free" period, or (c) reperfusing with 0.1 mM Ca2+, no protection was achieved by mannitol, DMTU, or desferrioxamine. Perfusion with N2 did not cause a reduction in CK release caused by caffeine or dinitrophenol or Ca2+ paradox. We conclude that no evidence supports the hypothesis that oxygen radicals are implicated in release of CK in Ca2+ paradox.
authors.affiliation: Zoology Department, School of Life Sciences, Liverpool University, England.
authors.forename: S
authors.initials: S
authors.lastname: Daniels
authors.forename: C J
authors.initials: CJ
authors.lastname: Duncan
mesh_terms: D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002374:Catalase / Q000494:pharmacology; D003402:Creatine Kinase / Q000378:metabolism*; D003676:Deferoxamine / Q000494:pharmacology; D004140:Dinitrophenols / Q000494:pharmacology; D016166:Free Radical Scavengers; D005609:Free Radicals; D066298:In Vitro Techniques; D008353:Mannitol / Q000494:pharmacology; D015428:Myocardial Reperfusion Injury / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000494:pharmacology; D013890:Thiourea / Q000031:analogs & derivatives / Q000494:pharmacology; D014810:Vitamin E / Q000494:pharmacology
chemical_list: D004140:Dinitrophenols; D016166:Free Radical Scavengers; D005609:Free Radicals; D014810:Vitamin E; D002110:Caffeine; D008353:Mannitol; C038983:1,3-dimethylthiourea; D002374:Catalase; D013482:Superoxide Dismutase; D003402:Creatine Kinase; D013890:Thiourea; D003676:Deferoxamine; D010100:Oxygen; D002118:Calcium