Toxic effect of hemoglobin on spinal cord neurons in culture.
The vulnerability of spinal cord neurons to hemoglobin was quantitatively assessed in primary cultures derived from fetal mice. Exposure to hemoglobin for 28 h in a serum-free medium resulted in concentration-dependent neuronal death, with an EC50 of 0.9 microM; glia were not injured. Neuronal death was decreased by the ferric iron chelator deferoxamine, the alpha-tocopherol analogue Trolox C, ascorbate, and exogenous catalase, but was potentiated by superoxide dismutase. Neuronal death was also increased by depletion of cellular glutathione with the gamma-glutamylcysteine synthetase inhibitor buthionine sulfoxamine; inhibition of endogenous catalase with 3-amino-1,2,4-triazole had no significant effect. These results suggest that hemoglobin is toxic to spinal neurons via an iron-dependent, oxidative mechanism involving a hydrogen peroxide intermediate, and support the hypothesis that hemoglobin release may contribute to neuronal loss after spinal cord trauma.
Regan
R F
RF
Division of Emergency Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Guo
Y
Y
D000704:Analysis of Variance; D000818:Animals; D002374:Catalase / Q000187:drug effects; D016923:Cell Death; D002478:Cells, Cultured; D004791:Enzyme Inhibitors; D005333:Fetus; D005978:Glutathione / Q000187:drug effects / Q000378:metabolism; D006454:Hemoglobins / Q000494:pharmacology / Q000633:toxicity*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D009474:Neurons / Q000187:drug effects* / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D013116:Spinal Cord / Q000187:drug effects* / Q000473:pathology; D013119:Spinal Cord Injuries / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology; D013482:Superoxide Dismutase / Q000378:metabolism
D004791:Enzyme Inhibitors; D006454:Hemoglobins; D007770:L-Lactate Dehydrogenase; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione