Dobutamine administration exacerbates postischaemic myocardial dysfunction in isolated rat hearts: an effect reversed by thyroxine pretreatment.
The present study has investigated the effects of dobutamine on postischaemic dysfunction in the setting of global ischaemia and reperfusion in a model of isolated heart preparation. Isolated rat hearts were subjected to 20 min of zero-flow global ischaemia followed by 45 min of reperfusion. Dobutamine administration (10 microg/kg/min) during the reperfusion period resulted in deterioration of functional recovery, which was abolished by propranolol administration. Long-term thyroxine pretreatment (12.5 microg 100 g(-1) body weight, b.i.d., s.c., for 2 weeks) reversed the detrimental effect of dobutamine and increased postischaemic recovery of function. We conclude that the combination of thyroxine pretreatment and dobutamine administration could potentially be a new therapeutic strategy to improve postischaemic dysfunction particularly in clinical settings such as cardiopulmonary bypass and/or myocardial infarction.
Pantos
Constantinos
C
Department of Pharmacology, University of Athens, 75 Mikras Asias Avenue, 11527 Goudi, Athens, Greece. cpantos@cc.uoa.gr
Mourouzis
Iordanis
I
Tzeis
Stylianos
S
Moraitis
Panagiotis
P
Malliopoulou
Vassiliki
V
Cokkinos
Demosthenis D
DD
Carageorgiou
Hariclia
H
Varonos
Dennis
D
Cokkinos
Dennis
D
D000818:Animals; D002316:Cardiotonic Agents / Q000009:adverse effects / Q000494:pharmacology*; D004280:Dobutamine / Q000009:adverse effects / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects* / Q000502:physiology / Q000503:physiopathology; D006352:Heart Ventricles / Q000187:drug effects / Q000503:physiopathology; D066298:In Vitro Techniques; D017202:Myocardial Ischemia / Q000150:complications; D015428:Myocardial Reperfusion Injury / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D013974:Thyroxine / Q000494:pharmacology*; D013997:Time Factors; D016276:Ventricular Function
D002316:Cardiotonic Agents; D004280:Dobutamine; D011433:Propranolol; D013974:Thyroxine