Rabbit model for in vivo study of anthracycline-induced heart failure and for the evaluation of protective agents

BACKGROUND: Cardiac toxicity associated with chronic administration of anthracycline (ANT) antibiotics represents a serious complication of their use in anticancer chemotherapy, but can also serve as a useful experimental model of cardiomyopathy and congestive heart failure. AIMS: In this study, a model of chronic ANT cardiotoxicity induced by repeated i.v. daunorubicin (DAU) administration to rabbits was tested. METHODS: Three groups of animals were used: (1) control group-10 animals received i.v. saline; (2) 11 animals received DAU (3 mg/kg, i.v.); (3) 5 animals received the model cardioprotective agent dexrazoxane (DEX, 60 mg/kg, i.p.), 30 min prior to DAU. All substances were administered once weekly, for 10 weeks. The DAU-induced heart damage and protective action of DEX were determined and quantitated with the use of histopathology, invasive haemodynamic measurements (e.g. left ventricular pressure changes-dP/dt(max), dP/dt(min)), non-invasive systolic function examinations (left ventricular ejection fraction, PEP/LVET index) and biochemical analysis of cardiac troponin T plasma concentrations. RESULTS: All the employed methods showed unambiguously pronounced heart impairment in the DAU group, with the development of both systolic and diastolic heart failure, as well as significant reduction of DAU-cardiotoxicity in DEX-pretreated animals. Other toxicities were acceptable. CONCLUSION: The presented model has been approved to be consistent and reliable and it can serve as a basis for future determinations and comparisons of chronic cardiotoxic effects of various drugs, as well as for the evaluation of potential cardioprotectants.