Anthracycline cardiotoxicity represents a serious risk of anticancer chemotherapy. The aim of the present pilot study was to compare the potential of both the left ventricular (LV) filling pattern evaluation and cardiac troponin T (cTnT) plasma levels determination for the early detection of daunorubicin-induced cardiotoxicity in rabbits. The echocardiographic measurements of transmitral LV inflow as well as cTnT determinations were performed weekly for 10 weeks in daunorubicin (3 mg/kg weekly) and control groups (n=5, each). Surprisingly, no significant changes in LV-filling pattern were observed through the study, most likely due to the xylazine-containing anesthesia, necessary for appropriate resolving of the E and A waves. In contrast to the echographic measurement, the dP/dt min index obtained invasively at the end of the study revealed a significant im pairment in LV relaxation, which was further supported by observed disturbances in myocardial collagen content and calcium homeostasis. However, at the same time cTnT plasma levels were progressively rising in the daunorubicin-treated animals from the 5th week (0.024±0.008 μg/l) until the end of the experiment (0.186±0.055 μg/l). Therefore, in contrast to complicated non-invasive evaluation of diastolic function, cTnT is shown to be an early and sensitive marker of anthracycline-induced cardiotoxicity in the rabbit model., M. Štěrba, T. Šimůnek, O. Popelová, A. Potáčová, M. Adamcová, Y. Mazurová, M. Holečková, V. Geršl., and Obsahuje bibliografii a bibliografické odkazy
Cardiotoxicity ranks among the most serious adverse effects of some cytostatics. The cardiac effects of repeated i.v. administration of a new antineoplastic agent, dimethoxybenfluron (once a week, 10 administrations), were investigated in rabbits with respect to cardiac function and the release of cardiac troponin T (cTnT). Different doses of dimethoxybenfluron were administered to two groups of animals (12 mg/kg; n = 7 and 24 mg/kg; n = 6) and compared with either a control group (saline 1 ml/kg; n = 6) or a group with experimentally induced cardiomyopathy (daunorubicin 50 mg/m2; n = 13). In daunorubicin-induced cardiomyopathy, cTnT levels in animals with premature deaths were significantly higher (0.31±0.11 mg/l) in comparison with the surviving animals (0.04±0.03 mg/l). However, cardiac TnT levels after the administration of dimethoxybenfluron in both doses were within the physiological range (lower than 0.1 mg/l) during the whole experiment as it was in the control group. The lack of cardiotoxicity of this new antineoplastic drug was supported by the absence of alterations in PEP:LVET ratio, left ventricle dP/dtmax or histological heart examination as well as by the fact that no premature death of animals occurred following repeated administration of dimethoxybenfluron. It is possible to conclude that no signs of cardiotoxicity were observed following repeated i.v. administration of dimethoxybenfluron., J. Macháčková, M. Adamcová, Y. Mazurová, R. Hrdina, M. Nobilis., and Obsahuje bibliografii