title: Characterization of the cardiac response to a low and high dose of dobutamine in the mouse model of dilated cardiomyopathy by MRI in vivo.
abstract: OBJECTIVE
  To assess the cardiac response to low (0.15-0.5 mg/kg i.p.) and high (1.5-20 mg/kg i.p.) doses of dobutamine in Tgαq*44 mice with dilated cardiomyopathy at the stage of advanced heart failure.
  
  
  METHODS
  Inotropic, lusitropic, and chronotropic response to β(1) -adrenergic stimulation was assessed by the cine magnetic resonance imaging (MRI) protocol based on the electrocardiogram (ECG)-triggered bright-blood images of one midventricular short-axis slice.
  
  
  RESULTS
  In wildtype mice increasing doses of dobutamine resulted in subsequent increase in the left ventricular function and heart rate acceleration, but significant inotropic, lusitropic, and chronotropic cardiac response was observed only after high doses of dobutamine, what is typical. In the Tgαq*44 mice low doses of dobutamine significantly increased inotropic and lusitropic cardiac performance without chronotropic changes. An increased heart rate was observed only after high doses of dobutamine, but then inotropic and lusitropic cardiac functional reserve was lost.
  
  
  CONCLUSIONS
  We described MRI stress test protocol based on a low and high dose of dobutamine induced response that proves useful in revealing alternation in cardiac function in mice with heart failure.
authors.affiliation: Department of Magnetic Resonance Imaging, Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland.
authors.forename: Urszula
authors.initials: U
authors.lastname: Tyrankiewicz
authors.forename: Tomasz
authors.initials: T
authors.lastname: Skorka
authors.forename: Magdalena
authors.initials: M
authors.lastname: Jablonska
authors.forename: Pawel
authors.initials: P
authors.lastname: Petkow-Dimitrow
authors.forename: Stefan
authors.initials: S
authors.lastname: Chlopicki
mesh_terms: D058665:Adrenergic beta-1 Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis / Q000473:pathology*; D004195:Disease Models, Animal; D004280:Dobutamine / Q000008:administration & dosage* / Q000494:pharmacology; D004562:Electrocardiography / Q000379:methods; D006321:Heart / Q000187:drug effects*; D006333:Heart Failure / Q000175:diagnosis / Q000473:pathology; D006339:Heart Rate; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D009206:Myocardium / Q000473:pathology; D011943:Receptors, Adrenergic, beta / Q000378:metabolism; D012984:Software; D016277:Ventricular Function, Left
chemical_list: D058665:Adrenergic beta-1 Receptor Agonists; D011943:Receptors, Adrenergic, beta; D004280:Dobutamine