title: Polynitroxylated pegylated hemoglobin: a novel neuroprotective hemoglobin for acute volume-limited fluid resuscitation after combined traumatic brain injury and hemorrhagic hypotension in mice.
abstract: OBJECTIVE
  Resuscitation of hemorrhagic hypotension after traumatic brain injury is challenging. A hemoglobin-based oxygen carrier may offer advantages. The novel therapeutic hemoglobin-based oxygen carrier, polynitroxylated pegylated hemoglobin (PNPH), may represent a neuroprotective hemoglobin-based oxygen carrier for traumatic brain injury resuscitation.
  
  
  OBJECTIVE
  1) PNPH is a unique non-neurotoxic hemoglobin-based oxygen carrier in neuronal culture and is neuroprotective in in vitro neuronal injury models. 2) Resuscitation with PNPH would require less volume to restore mean arterial blood pressure than lactated Ringer's or Hextend and confer neuroprotection in a mouse model of traumatic brain injury plus hemorrhagic hypotension.
  
  
  METHODS
  Prospective randomized, controlled experimental study.
  
  
  METHODS
  University center.
  
  
  RESULTS
  In rat primary cortical neuron cultures, control bovine hemoglobin was neurotoxic (lactate dehydrogenase release; 3-[4,5-dimethylthiazol-2-yl-]-2,5-diphenyltetrazolium bromide assay) at concentrations from 12.5 to 0.625 μM, whereas polyethylene glycol-conjugated hemoglobin showed intermediate toxicity. PNPH was not neurotoxic (p<.05 vs. bovine hemoglobin and polyethylene glycol hemoglobin; all concentrations). PNPH conferred neuroprotection in in vitro neuronal injury (glutamate/glycine exposure and neuronal stretch), as assessed via lactate dehydrogenase and 3-[4,5-dimethylthiazol-2-yl-]-2,5-diphenyltetrazolium bromide (all p<.05 vs. control). C57BL6 mice received controlled cortical impact followed by hemorrhagic hypotension (2 mL/100 g, mean arterial blood pressure ∼35-40 mm Hg) for 90 min. Mice were resuscitated (mean arterial blood pressure>50 mm Hg for 30 min) with lactated Ringer's, Hextend, or PNPH, and then shed blood was reinfused. Mean arterial blood pressures, resuscitation volumes, blood gasses, glucose, and lactate were recorded. Brain sections at 7 days were examined via hematoxylin and eosin and Fluoro-Jade C (identifying dying neurons) staining in CA1 and CA3 hippocampus. Resuscitation with PNPH or Hextend required less volume than lactated Ringer's (both p<.05). PNPH but not Hextend improved mean arterial blood pressure vs. lactated Ringer's (p<.05). Mice resuscitated with PNPH had fewer Fluoro-Jade C positive neurons in CA1 vs. Hextend and lactated Ringer's, and CA3 vs. Hextend (p<.05).
  
  
  CONCLUSIONS
  PNPH is a novel neuroprotective hemoglobin-based oxygen carrier in vitro and in vivo that may offer unique advantages for traumatic brain injury resuscitation.
authors.affiliation: Safar Center for Resuscitation Research, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, USA.
authors.forename: David K
authors.initials: DK
authors.lastname: Shellington
authors.forename: Lina
authors.initials: L
authors.lastname: Du
authors.forename: Xianren
authors.initials: X
authors.lastname: Wu
authors.forename: Jennifer
authors.initials: J
authors.lastname: Exo
authors.forename: Vincent
authors.initials: V
authors.lastname: Vagni
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.forename: Keri
authors.initials: K
authors.lastname: Janesko-Feldman
authors.forename: Robert S B
authors.initials: RS
authors.lastname: Clark
authors.forename: Hülya
authors.initials: H
authors.lastname: Bayir
authors.forename: C Edward
authors.initials: CE
authors.lastname: Dixon
authors.forename: Larry W
authors.initials: LW
authors.lastname: Jenkins
authors.forename: Carleton J C
authors.initials: CJ
authors.lastname: Hsia
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Kochanek
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001930:Brain Injuries / Q000150:complications / Q000188:drug therapy*; D002470:Cell Survival; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D058734:Exsanguination / Q000150:complications / Q000188:drug therapy*; D006454:Hemoglobins / Q000494:pharmacology / Q000627:therapeutic use*; D007022:Hypotension / Q000188:drug therapy / Q000209:etiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D009589:Nitrogen Oxides / Q000494:pharmacology / Q000627:therapeutic use; D011092:Polyethylene Glycols / Q000494:pharmacology / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D012151:Resuscitation / Q000379:methods
chemical_list: D006454:Hemoglobins; D018696:Neuroprotective Agents; D009589:Nitrogen Oxides; C557204:polynitroxylated pegylated hemoglobin; D011092:Polyethylene Glycols