Stereology and morphometry of the musculoskeletal tissue of animals submitted to a strength training program and creatine supplementation for 9 weeks

Abstract

Creatine may promote ergogenic effects in the practice of high intensity exercise. However, there is little evidence to report on the morphometric and stereological effects of the association of these components in experimental models. Twenty-four Wistar rats, aged 15 weeks and under controlled feeding and hydration conditions, were selected. To verify the morphometric and stereological modifications, the animals were classified into four groups: control, supplemented, training, and training and supplemented. Creatine supplemented animals were supplemented (via gavage) at dosages of 300 mg/kg body mass for nine weeks, and the same training period as the animals that were trained performed a training program based on the studies of Honenberg & Farrar. After the experimentation period, the animals rested for 48 hours and the latissimus dorsi and biceps brachii muscles were excised, which were later submitted to the cryostat histological section protocol, followed by hematoxylin and eosin staining. The morphometric results indicated few modifications of the nuclear area for the groups of the experiment, presenting statistical difference only the trained and supplemented group in relation to the other groups of the study. Sarcoplasmic perimetry was also more evident in the group undergoing both treatments. The stereological analysis verified the presence of some mononuclear phagocytes in the muscular tissue, without, however, presenting conditions of severe tissue inflammation. We concluded, therefore, that creatine has more evident morphometric effects when associated with strength training.