title: Significant contamination of superoxide dismutases and catalases with lipopolysaccharide-like substances.
abstract: Commercially available superoxide dismutase (SOD) and catalase induced remarkable morphological changes in cultured peritoneal resident macrophages (PRMs). The morphology resembled that of cells stimulated with various macrophage-activating substances such as bacterial lipopolysaccharides (LPS). PRMs treated with SOD and catalase for 24 h produced a significant amount of nitric oxide. Peritoneal thioglycollate-exudated macrophages (PEMs) that were induced to die by combined treatment with LPS and cycloheximide (protein synthesis inhibitor) were killed by the treatment with SOD and catalase in the presence of cycloheximide. The effect of SOD and catalase was heat-resistant and was not found in PEMs of the C3H/HeJ mouse, an LPS low responder strain. These results strongly indicated the presence of LPS-like substances in the sample of SOD and catalase used. An examination of commercially available SOD and catalase samples for the presence of LPS-like substances demonstrated that many were contaminated. The LPS contamination was directly confirmed by bacterial endotixins test. It is quite important to take into consideration that commercially available SODs and catalases may be contaminated with LPS and the contaminants may affect the results of studies.
authors.affiliation: Environmental and Toxicological Sciences Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan. y_kubota@nirs.go.jp
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Kubota
authors.forename: Sentaro
authors.initials: S
authors.lastname: Takahashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sato
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002374:Catalase / Q000737:chemistry / Q000633:toxicity*; D004340:Drug Contamination; D005260:Female; D008070:Lipopolysaccharides / Q000032:analysis / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008809:Mice, Inbred C3H; D009569:Nitric Oxide / Q000378:metabolism; D013045:Species Specificity; D013482:Superoxide Dismutase / Q000737:chemistry / Q000633:toxicity*
chemical_list: D008070:Lipopolysaccharides; D009569:Nitric Oxide; D002374:Catalase; D013482:Superoxide Dismutase