title: Assessment of hemoglobin-dependent neurotoxicity: alpha-alpha crosslinked hemoglobin.
abstract: Adult human hemoglobin A0 (HbA0) has been shown to be neurotoxic, and we wish to report on similar studies conducted using a modified hemoglobin, which has been crosslinked between the alpha subunits (alpha-alpha Hb). Cortical cell cultures were prepared from fetal Swiss-Webster mice at 15-16 days gestation. Mature cultures (days in vitro, 12-16) were exposed to alpha-alpha Hb in a defined medium for 24-48 hours at 37 degrees C. Low micromolar amounts of alpha-alpha Hb were neurotoxic in a concentration-dependent fashion. This toxicity was attenuated by the antioxidants Trolox and U-74500A and by the iron chelator deferoxamine. The hemoglobin-binding protein, haptoglobin, also completely blocked alpha-alpha Hb-dependent neurotoxicity. The latter result was unexpected because complex formation between alpha-alpha Hb and haptoglobin was not detected using assays of haptoglobin fluorescence and hemoglobin peroxidase activity.
authors.affiliation: Blood Research Division, Letterman Army Institute of Research, Presidio of San Francisco, CA.
authors.forename: S S
authors.initials: SS
authors.lastname: Panter
authors.forename: K D
authors.initials: KD
authors.lastname: Vandegriff
authors.forename: P O
authors.initials: PO
authors.lastname: Yan
authors.forename: R F
authors.initials: RF
authors.lastname: Regan
mesh_terms: D000328:Adult; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001802:Blood Substitutes / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D002839:Chromans / Q000494:pharmacology; D003432:Cross-Linking Reagents; D003676:Deferoxamine / Q000494:pharmacology; D006242:Haptoglobins / Q000378:metabolism / Q000494:pharmacology; D006441:Hemoglobin A / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D006801:Humans; D051379:Mice; D011281:Pregnatrienes / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D001802:Blood Substitutes; D002839:Chromans; D003432:Cross-Linking Reagents; D006242:Haptoglobins; D011281:Pregnatrienes; D006441:Hemoglobin A; C053356:U 74500A; D003676:Deferoxamine; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid