[Effect of enalaprilat on cardiotoxicity induced by doxorubicin]

To evaluate whether the enalaprilat, an angiotensin converting enzyme inhibitor, was able to prevent the myocardial damage induced by doxorubicin (DOX).

Four groups composed of 10 Wistar rats each were followed for seven weeks: control (CONT); treated with enalaprilat (ENA, 1mg/kg/d/sc) treated with doxorubicin (DOX, 25 mg/kg/d/sc), and treated with doxorubicin plus enalaprilat (DOX+ENA). In eight animals of each group, the left ventricle (LV) was prepared for morphometric study and stained with HE and picro-sírius for identifying muscle fibers and collagen. In each group three fragments of the LV were examined with electronic microscopy (EM). For statistical analysis: the one-way analysis of variance was performed and was followed by multiple comparisons test when the difference between groups were detected p values < or = 0.05 were considered significant.

Light microscopy-it was not found any significant difference among the groups for muscle fibers patterns and proportion of collagen fibers of left ventricle. Electronic microscopy-the cristolysis index (proportion between normal and damage mitochondria) demonstrated significant difference between DOX and DOX+ENA groups (30.1 vs 11.6, p < or = 0.01).

ENA prevented cardiotoxic alterations induced by DOX minimizing the aggression to the mitochondria and these findings, if confirmed in anima nobilis, may open a new clinical use for this type of drug.