title: Effect of amrinone and milrinone on myocardial ischemia extent and infarct size in isolated rabbit hearts.
abstract: The effect of inotropics on myocardial ischemia is difficult to predict, since inotropics may influence the determinants of myocardial O2-demand and O2-supply differently. Several phosphodiesterase-inhibitors have been reported to possess antiischemic properties related in vivo to their hemodynamic and O2-sparing effects. The effects of amrinone (CAS 60719-84-8) (10(-6) mol/l or 5 x 10(-5) mol/l) or milrinone (CAS 78415-72-2) 10(-5) mol/l) on myocardial ischemia extent and infarct size were compared in isolated electrically paced rabbit hearts (Langendorff, constant pressure: 70 cm H2O, Tyrode solution, Ca2+ 1.8 mmol/l). Myocardial ischemia was induced by left coronary artery branch occlusion and quantitated from epicardial NADH-fluorescence photography. Infarct size was determined by Evan's blue dye and nitroblue-tetrazolium staining and planimetry. At low concentration (10(-6) mol/l), amrinone had no significant influence on left ventricular pressure or coronary flow (p < 0.05) and epicardial NADH-fluorescence area or infarct size were not significantly affected compared to controls (p > 0.05). Amrinone (5 x 10(-5) mol/l) or milrinone (10(-5) mol/l) significantly increased left ventricular pressure (+10%, p < 0.05) and coronary flow (+30, 40%, p < 0.05) to a similar extent. Concomitantly, both agents similarly reduced epicardial NADH-fluorescence area (-25%, p < 0.05) and infarct size relative to the area at risk or ventricle size compared to controls (p < 0.05).
  
  
  CONCLUSIONS
  amrinone or milrinone possess comparable antiischemic effects in isolated rabbit hearts that seem to be related to coronary dilator activity of these agents.
authors.affiliation: Institut für Pharmakologie, Universität Köln, Fed. Rep. of Germany.
authors.forename: A F
authors.initials: AF
authors.lastname: Rump
authors.forename: B
authors.initials: B
authors.lastname: Blazincic
authors.forename: W
authors.initials: W
authors.lastname: Klaus
mesh_terms: D000676:Amrinone / Q000494:pharmacology*; D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D003326:Coronary Circulation / Q000187:drug effects / Q000502:physiology; D005453:Fluorescence; D006439:Hemodynamics / Q000187:drug effects; D006651:Histocytochemistry; D066298:In Vitro Techniques; D008297:Male; D020105:Milrinone; D009203:Myocardial Infarction / Q000473:pathology* / Q000503:physiopathology; D017202:Myocardial Ischemia / Q000473:pathology* / Q000503:physiopathology; D009243:NAD / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D011728:Pyridones / Q000494:pharmacology*; D011817:Rabbits
chemical_list: D002316:Cardiotonic Agents; D011728:Pyridones; D009243:NAD; D020105:Milrinone; D000676:Amrinone