title: Angiotensin converting enzyme inhibitors as oxygen free radical scavengers.
abstract: The authors have compared the ability of two non-SH-containing angiotensin converting enzyme (ACE) inhibitors (enalaprilat and lisinopril) with an -SH containing ACE inhibitor (captopril) to scavenge the hydroxyl radical (.OH). All three compounds were able to scavenge .OH radicals generated in free solution at approximately diffusion-controlled rates (10(10) M-1 s-1) as established by the deoxyribose assay in the presence of EDTA. The compounds also inhibited deoxyribose degradation in reaction mixtures which did not contain EDTA but not so effectively. This later findings also suggests that they have some degree of metal-binding capability. Chemiluminescence assays of oxidation of hypoxanthine by xanthine oxidase in the presence of luminol, confirm that the three ACE inhibitors are oxygen free radical scavengers. Our results indicate that the presence of a sulphydryl group in the chemical structure of ACE inhibitors is not relevant for their oxygen free radical scavenging ability.
authors.affiliation: Instituto de Química Fisiológica, Faculdade de Medicina, Lisboa-Portugal.
authors.forename: M L
authors.initials: ML
authors.lastname: Mira
authors.forename: M M
authors.initials: MM
authors.lastname: Silva
authors.forename: M J
authors.initials: MJ
authors.lastname: Queiroz
authors.forename: C F
authors.initials: CF
authors.lastname: Manso
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D002216:Captopril / Q000494:pharmacology; D002374:Catalase / Q000494:pharmacology; D002712:Chlorides; D003855:Deoxyribose / Q000378:metabolism; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D015773:Enalaprilat / Q000494:pharmacology; D005290:Ferric Compounds / Q000494:pharmacology; D016166:Free Radical Scavengers; D017665:Hydroxyl Radical / Q000378:metabolism; D019271:Hypoxanthine; D007042:Hypoxanthines / Q000378:metabolism; D017706:Lisinopril / Q000494:pharmacology; D008163:Luminescent Measurements; D013482:Superoxide Dismutase / Q000378:metabolism; D014969:Xanthine Oxidase / Q000378:metabolism
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D002712:Chlorides; D005290:Ferric Compounds; D016166:Free Radical Scavengers; D007042:Hypoxanthines; D019271:Hypoxanthine; D017665:Hydroxyl Radical; D003855:Deoxyribose; D004492:Edetic Acid; D002216:Captopril; D017706:Lisinopril; D002374:Catalase; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D015773:Enalaprilat; C024555:ferric chloride; D004121:Dimethyl Sulfoxide