title: Crystalloid versus red blood cell-containing medium in the Langendorff-perfused isolated heart preparation.
abstract: BACKGROUND
  The isolated heart model is widely used for the assessment of coronary vascular response under various experimental conditions. As medium perfusate influences oxygenation conditions, coronary vascular response and myocardial consumption performance may differ between isolated hearts perfused with from with Krebs-Henseleit solution or Krebs-Henseleit mixed with red blood cells (KH-RBC).
  
  
  METHODS
  Coronary vascular response to endothelium-dependent and independent vasodilators as well as myocardial performance and oxygen consumption to isoproterenol infusion were compared in isolated rabbit hearts perfused with Krebs-Henseleit or KH-RBC. Krebs-Henseleit perfusate was equilibrated with 95% oxygen and 5% carbon dioxide, KH-RBC (haemoglobin 8.0 +/- 1.1 g.dl) with 20% oxygen, 5% carbon dioxide, and 75% nitrogen. The perfusion pressure was kept constant so that coronary blood flow (CBF) varied with coronary resistance. Data are mean +/- SD.
  
  
  RESULTS
  Bradykinin induced a greater increase in CBF in KH-RBC-perfused hearts than in Krebs-Henseleit-perfused hearts (263 +/- 78 versus 134 +/- 35% of baseline, P < 0.001). Sodium nitroprusside induced a greater increase in CBF in KH-RBC-perfused than in Krebs-Henseleit-perfused hearts (257 +/- 70 versus 174 +/- 31% of baseline, P < 0.001). The increases in myocardial performance and in oxygen consumption induced by isoproterenol were greater with KH-RBC-perfused hearts than in Krebs-Henseleit-perfused hearts. A greater myoglobin release was observed in Krebs-Henseleit-perfused hearts.
  
  
  CONCLUSIONS
  Endothelium-dependent and independent coronary flow responses are increased in KH-RBC-perfused hearts. Moreover, metabolic control of CBF is altered in Krebs-Henseleit-perfused hearts. Such differences should be taken into account when pharmacologic responses of anaesthetic agents are studied.
authors.affiliation: Université Pierre et Marie Curie-Paris, Université René Diderot, Paris, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Mouren
authors.forename: Eric
authors.initials: E
authors.lastname: Vicaut
authors.forename: Lionel
authors.initials: L
authors.lastname: Lamhaut
authors.forename: Bruno
authors.initials: B
authors.lastname: Riou
authors.forename: Alexandre
authors.initials: A
authors.lastname: Ouattara
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis; D003326:Coronary Circulation / Q000502:physiology; D000077324:Crystalloid Solutions; D003470:Culture Media / Q000737:chemistry; D004727:Endothelium / Q000473:pathology*; D004730:Endothelium, Vascular / Q000473:pathology; D004912:Erythrocytes / Q000166:cytology* / Q000473:pathology; D007552:Isotonic Solutions / Q000737:chemistry; D008297:Male; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D009211:Myoglobin / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010101:Oxygen Consumption; D010477:Perfusion; D011817:Rabbits
chemical_list: D000077324:Crystalloid Solutions; D003470:Culture Media; D007552:Isotonic Solutions; D009211:Myoglobin; D010100:Oxygen