RÉSUMÉ
The use of anabolic androgenic steroids (AAS) has grown into aworldwide substance abuse problem over the last decades, with the doses taken by illegal users being 10 to 100 times higher than the therapeutic ones. In the present experiment, 60 mice were divided into 3 groups of 20 animals. Group 1 received testosterone cypionate (Deposteron [EMS, São Bernardo do Campo, SP, Brazil]); group 2 received stanozolol (Stanozolol Depot, Landerlan, Lambaré, Paraguay), and group 3 received saline solution), each one composed by 10males and 10 females, treated once a week and put to swimming thrice a week for 2months. After euthanasia, their chests were opened, the hearts removed and processed histologically for morphometric analyses. The specimens were cut into 6 different sections and each onewas measured with the help of an optical microscope with a 40-fold magnification. For such analyses, the Axiovision Rel. 4.8.2 (Carl Zeiss Microscopy LLC, Peabody, MA, USA) and Axiovision 4 Module Interactive Measurement (Carl Zeiss Microscopy LLC) software were used. The results showed that there was an increase in the diameter of the left ventricles in the male mice treated with Deposteron while in the female animals treated with Winstrol, there was a decrease in the left ventricular diameter in relation to the other two groups. Thus, one can conclude that the use of supraphysiological doses of the given AAS significantly alters the ventricular diameter in both male and female animals, which can cause a considerable change in both heart rate and blood pressure, and potentially induce disorders that are very relevant to the organism.