Early detection of anthracycline cardiotoxicity in a rabbit model: left ventricle filling pattern versus troponin T determination.
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.