title: Major contribution of vasospasm-induced coronary blood flow reduction to anaphylactic ventricular dysfunction assessed in isolated blood-perfused rat heart.
abstract: BACKGROUND
  Cardiac anaphylaxis is accompanied by coronary spasm and decreased left ventricular (LV) contractility. However, it has not been determined experimentally whether LV dysfunction during anaphylaxis is induced mainly by reduced coronary blood flow (CBF) or direct negative inotropic actions of chemical mediators. To demonstrate the major role of CBF reduction in anaphylactic LV dysfunction, we determined LV contractility during anaphylaxis and forcible CBF reduction maneuver to reproduce the anaphylaxis-induced CBF reduction in isolated blood-perfused rat hearts.
  
  
  METHODS
  Isolated hearts from Wistar rats in the ovalbumin-sensitized anaphylaxis, non-sensitized flow reduction, and non-sensitized time control group were subjected to coronary perfusion with blood at a constant pressure and measurements of CBF and LV pressure. Cardiac anaphylaxis was induced by intracoronary injections of ovalbumin antigen.
  
  
  RESULTS
  In response to antigen administrations, sensitized anaphylaxis group rat hearts showed decreases in CBF and the maximum increasing rate of systolic LV pressure (dP/dtmax) with an increased coronary vascular resistance as evidence of coronary spasm. The non-sensitized flow reduction group rat hearts whose CBF was forcibly reduced as in anaphylaxis showed the same degree of dP/dtmax reduction.
  
  
  CONCLUSIONS
  The contractile failure during cardiac anaphylaxis is caused mainly by decreased CBF due to coronary spasm.
authors.forename: Yuhichi
authors.initials: Y
authors.lastname: Kuda
authors.affiliation: Department of Physiology II, Kanazawa Medical University, Ishikawa, Japan. yasu@kanazawa-med.ac.jp.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Kurata
authors.forename: Mofei
authors.initials: M
authors.lastname: Wang
authors.forename: Mamoru
authors.initials: M
authors.lastname: Tanida
authors.forename: Toshishige
authors.initials: T
authors.lastname: Shibamoto
mesh_terms: D000707:Anaphylaxis / Q000150:complications* / Q000503:physiopathology; D000818:Animals; D003326:Coronary Circulation / Q000502:physiology*; D003329:Coronary Vasospasm / Q000150:complications* / Q000503:physiopathology; D004195:Disease Models, Animal; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000209:etiology* / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology*