title: The effects of hemodilution with polyethylene glycol bovine hemoglobin (PEG-Hb) in a conscious porcine model.
abstract: BACKGROUND
  Severe hemodilution in large mammals has been used rigorously for the safety and efficacy testing of hemoglobin-based red blood cell substitutes. The effects of hemodilution with polyethylene glycol-modified bovine hemoglobin (PEG-Hb) were investigated in an unanesthetized porcine model.
  
  
  METHODS
  Immature Yorkshire cross barrow pigs were subjected to exchange transfusion with PEG-Hb (n = 6) or dextran 70 (n = 4) until an 80% reduction in hematocrit was achieved.
  
  
  RESULTS
  All six (100%) PEG-Hb-infused pigs and only one (25%) dextran 70 control pig survived the resultant reduction in erythrocytes. Heart rates and mean arterial pressure were not significantly affected by PEG-Hb infusion. Pigs infused with PEG-Hb maintained normal levels of blood pH, PO2, and PCO2 while dextran 70 controls showed low PvO2, PaCO2, and the development of acidosis. Histological evaluation revealed that the surviving dextran 70 control animal exhibited possible anoxia-induced hepatic centrilobular necrosis. PEG-Hb-treated pigs demonstrated the presence of renal tubular cell cytoplasmic vacuoles and vacuolated macrophages in spleens.
  
  
  CONCLUSIONS
  The results indicate that PEG-Hb effectively supports life close to lethal levels of anemia.
authors.affiliation: Formulations-Toxicology Department, Enzon Incorporated, Piscataway, NJ 08854, USA.
authors.forename: C D
authors.initials: CD
authors.lastname: Conover
authors.forename: P
authors.initials: P
authors.lastname: Malatesta
authors.forename: L
authors.initials: L
authors.lastname: Lejeune
authors.forename: C L
authors.initials: CL
authors.lastname: Chang
authors.forename: R G
authors.initials: RG
authors.lastname: Shorr
mesh_terms: D000818:Animals; D002417:Cattle; D003911:Dextrans / Q000627:therapeutic use; D004353:Drug Evaluation, Preclinical; D005078:Exchange Transfusion, Whole Blood / Q000379:methods / Q000706:statistics & numerical data; D006438:Hemodilution / Q000379:methods* / Q000706:statistics & numerical data; D006439:Hemodynamics / Q000187:drug effects; D006454:Hemoglobins / Q000627:therapeutic use*; D014677:Pharmaceutical Vehicles; D010952:Plasma Substitutes / Q000627:therapeutic use; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D011897:Random Allocation; D013552:Swine
chemical_list: D003911:Dextrans; D006454:Hemoglobins; C109960:PEG-hemoglobin; D014677:Pharmaceutical Vehicles; D010952:Plasma Substitutes; D011092:Polyethylene Glycols