title: Methylene blue administration in the compound 48/80-induced anaphylactic shock: hemodynamic study in pigs.
abstract: OBJECTIVE
  To verify if the methylene blue (MB) administration prevents and/or reverses the compound 48/80 (C48/80)-induced anaphylactic shock in pigs.
  
  
  METHODS
  Female Dalland pigs were anesthetized and had the hemodynamic parameters recorded during the necessary time to administer some drugs and observe their effect. The animals were randomly assigned to one of the five groups: 1) control; 2) MB: the animals received a bolus injection of MB (2 mg/kg) followed by continuous infusion of MB (2.66 mg/Kg/h delivered by syringe infusion pump); 3) C48/80: the animals received a bolus injection of C48/80 (4 mg/kg); 4) C48/80+MB: the animals received a bolus injection of C48/80 (4 mg/kg) and 10 minutes after the C48/80 administration the animals received a bolus injection of MB (2 mg/kg) followed by continuous infusion of MB (2.66 mg/Kg/h delivered by syringe infusion pump); 5) MB+C48/80: the animals received a bolus injection of MB (2 mg/kg) and 3 minutes later they received a bolus injection of C48/80 (4 mg/kg).
  
  
  RESULTS
  The intravenous infusion of MB alone caused no changes in the mean arterial pressure (MAP) showing that the administered MB dose was safe in this experimental model. The C48/80 was effective in producing experimental anaphylactic shock since it was observed a decrease in both MAP and cardiac output (CO) after its administration. The MB did not prevent or reverse the C48/80-induced anaphylactic shock in this model. In fact, the MAP of the animals with anaphylactic shock treated with MB decreased even more than the MAP of the animals from the C48/80 group. On the other hand, the C48/80-induced epidermal alterations disappeared after the MB infusion.
  
  
  CONCLUSIONS
  Despite our data, the clinical manifestations improvement brings some optimism and does not allow excluding the MB as a possible therapeutic option in the anaphylactic shock.
authors: Department of Surgery and Anatomy, FMRP, USP, Ribeirao Preto, SP, Brazil.
authors: Antonio Carlos
authors: AC
authors: Menardi
authors: Verena Kise
authors: VK
authors: Capellini
authors: Andrea Carla
authors: AC
authors: Celotto
authors: Agnes Afrodite Sumarelli
authors: AA
authors: Albuquerque
authors: Fernanda
authors: F
authors: Viaro
authors: Walter Vilella A
authors: WV
authors: Vicente
authors: Alfredo José
authors: AJ
authors: Rodrigues
authors: Paulo Roberto Barbosa
authors: PR
authors: Evora
mesh_terms: D000707:Anaphylaxis / Q000139:chemically induced / Q000188:drug therapy* / Q000517:prevention & control; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004195:Disease Models, Animal; D005260:Female; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D008751:Methylene Blue / Q000627:therapeutic use*; D011897:Random Allocation; D013552:Swine; D013997:Time Factors; D014655:Vascular Resistance / Q000187:drug effects; D003189:p-Methoxy-N-methylphenethylamine / Q000037:antagonists & inhibitors / Q000633:toxicity*
chemical_list: D003189:p-Methoxy-N-methylphenethylamine; D008751:Methylene Blue