title: Extraction and analysis of superoxide free radicals (.O2-) from whole mammalian liver.
abstract: Extraction of whole lobes of normal rat liver with dimethyl sulphoxide (DMSO) under N2 gives extracts which contain 5-10 mumol/l.O2- (50-100 nmol.O2- per 10 ml extract per 4 g liver; 1.25-2.50 nmol.O2- per millilitre per gram liver). Evidence for .O2- in the extracts is given by: (1) electron spin resonance signals (ESR), (2) differential pulse polarography (DPP), (3) chemiluminescence (CL), and (4) nitroblue tetrazolium reduction (NBT). All tests yield results identical with those obtained with authentic .O2-. Extraction of .O2- is enhanced by tetrabutyl ammonium ion, and is maximal at 1-3 min. These results raise the possibility that substantial amounts of .O2- are normally sequestered in protective membranous sites in vivo.
authors.affiliation: Health Protection Section, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27103.
authors.forename: A R
authors.initials: AR
authors.lastname: Shoaf
authors.forename: A U
authors.initials: AU
authors.lastname: Shaikh
authors.forename: R D
authors.initials: RD
authors.lastname: Harbison
authors.forename: O
authors.initials: O
authors.lastname: Hinojosa
mesh_terms: D000818:Animals; D004121:Dimethyl Sulfoxide; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D008099:Liver / Q000737:chemistry*; D008163:Luminescent Measurements; D008297:Male; D009580:Nitroblue Tetrazolium; D010084:Oxidation-Reduction; D011048:Polarography; D051381:Rats; D011919:Rats, Inbred Strains; D013481:Superoxides / Q000032:analysis*
chemical_list: D005609:Free Radicals; D013481:Superoxides; D009580:Nitroblue Tetrazolium; D004121:Dimethyl Sulfoxide