Ultrastructural and morphometric investigations on the effects of training and administration of anabolic steroids on the myocardium of guinea pigs.

The effects on the myocardium of guinea pigs of a training program, of the administration of anabolic steroids (Dianabol), and of both combined were investigated at the ultrastructural level. Quantitative electron microscopy showed an enlargement of the sarcoplasmic space in all experimental groups and a disbalance of the mitochondrial/myofibrillar ratio in favor of the mitochondria, which was most pronounced after administration of anabolic steroids. The augmentation of the mitochondrial volume was assumed to occur by fusion, hypertrophy, and development of new mitochondria. When the administration of anabolic steroids and training were combined, some myocardial cells were pathologically altered; destructed mitochondria and aberrant myofibrils were found. Focally dehiscent intercalated discs and necrotic cells were also observed. It is suggested from these findings that the administration of anabolic steroids in competitive sports may lead to pathological alterations in the myocardium.