Anatomopathological study of cardiomyopathy induced by doxorubicin in rats

Purpose: The development of an experimental model of myocardiopathy induced by Doxorubicin in rats. Methods: 16 wistar male rats were randomized in two groups: Group I (placebo) and Group II (Doxorubicin - 5mg/kg). After six months, the animals were subjected to cardiotomy and their hearts were weighted and submitted to transversal cuts, from which fragments for a macro and micro study were obtained. These fragments were studied considering their external and internal diameters and the thickness of the left ventricle (LV). The histological pieces were analyzed for the presence of fibrosis, cytoplasmic vacuolization, necrosis and size of nucleus variation. Data obtained was submitted to statistical analysis with Student's t test. Results: The hearts of the animals in Group II increased 41% in relation to their weight; 33% in the internal diameter and 14% in the external diameter of the LV cavity; and 24% in the thickness of the wall. Fibrosis of the myocardial tissue was observed in 75% of the animals of Group II; all the animals presented miocyte cytoplasmatic vacuolization; myocardial necrosis was present in 75% of the animals; and 87/% presented variation in the size of myocite nuclei. The presence of polymorphonuclear cells was also observed. Conclusion: Doxorubicin was effective in the promotion of macro and microscopic alterations in the cardiac tissue of rats, possibly constituting a model for the experimental study of myocardiopathy.