title: Evaluation of neuronal apoptosis precursors in an experimental model of acute normovolemic hemodilution.
abstract: BACKGROUND
  The effects of acute anemia on neuronal cells and the safe limits of hematocrit are not well established. The objective of this study was to evaluate neuronal pro- and anti-apoptotic Bax and Bcl-x proteins, caspase-3 and -9 activity, and DNA fragmentation after acute normovolemic hemodilution (ANH).
  
  
  METHODS
  Twenty-four pigs were anesthetized and randomized into 4 groups: Sham, ANH to 15% hematocrit (ANH15%), ANH to 10% hematocrit (ANH10%) and hypoxia (Hx). ANH was achieved by simultaneous blood withdrawal and hydroxyethyl starch infusion. Hx consisted of ventilation with a 6% inspired oxygen fraction for 60 minutes. Bax and Bcl-x proteins as well as DNA fragmentation were evaluated in cortical nuclear and mitochondrial fractions. Caspase-3 and -9 activity was evaluated in the cortical mitochondrial and hippocampal cytosolic fractions. The data were compared using analysis of variance followed by Tukey's test (P<0.05).
  
  
  RESULTS
  No changes were observed in Bax protein expression after hemodilution in the ANH15% and ANH10% groups compared to the Sham group. Bax expression in the Hx group was increased in the nuclear and mitochondrial fractions compared to all other groups. No significant difference was observed in Bcl-x expression. Caspase-3 and -9 activity in the cytosolic and mitochondrial fractions was different in the Hx group compared to all other groups. No statistical significance in DNA fragmentation was found among the Sham, ANH15% or ANH10% groups.
  
  
  CONCLUSIONS
  ANH to 10 and 15% hematocrit did not induce alterations in apoptosis precursors, suggesting that cerebral oxygenation was preserved during these anemic states.
authors.affiliation: LIM08-Laboratory of Anesthesiology, Department of Anesthesia and Surgical Intensive Care, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Fabrício O
authors.initials: FO
authors.lastname: Frazilio
authors.affiliation: LIM08-Laboratory of Anesthesiology, Department of Anesthesia and Surgical Intensive Care, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Denise Aya
authors.initials: DA
authors.lastname: Otsuki
authors.affiliation: LIM08-Laboratory of Anesthesiology, Department of Anesthesia and Surgical Intensive Care, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Jessica
authors.initials: J
authors.lastname: Noel-Morgan
authors.affiliation: LIM45-Neuroregeneration Center, Department of Neurology, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Jessica Ruivo
authors.initials: JR
authors.lastname: Maximino
authors.affiliation: LIM45-Neuroregeneration Center, Department of Neurology, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Gabriela Pintar
authors.initials: GP
authors.lastname: Oliveira
authors.affiliation: LIM45-Neuroregeneration Center, Department of Neurology, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Gerson
authors.initials: G
authors.lastname: Chadi
authors.affiliation: LIM08-Laboratory of Anesthesiology, Department of Anesthesia and Surgical Intensive Care, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Jose Otavio Costa
authors.initials: JO
authors.lastname: Auler
authors.affiliation: LIM08-Laboratory of Anesthesiology, Department of Anesthesia and Surgical Intensive Care, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Denise Tabacchi
authors.initials: DT
authors.lastname: Fantoni
mesh_terms: D000740:Anemia / Q000097:blood* / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D001784:Blood Gas Analysis; D001810:Blood Volume; D001921:Brain / Q000378:metabolism*; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D005625:Frontal Lobe / Q000378:metabolism; D015870:Gene Expression; D006400:Hematocrit; D006439:Hemodynamics; D006624:Hippocampus / Q000378:metabolism; D000860:Hypoxia / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D013552:Swine; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism; D051020:bcl-X Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; D053148:Caspase 3; D053453:Caspase 9