Effects of nandrolone decanoate on the neuromuscular junction of rats submitted to swimming.

摘要: This study addressed the effects of nandrolone decanoate (ND) on contractile properties and muscle fiber characteristics rats submitted to swimming. Male Wistar were grouped in sedentary (S), swimming (Sw), sedentary+ND (SND), swimming+ND (SwND), six animals per group. ND (3 mg/kg) was injected (subcutaneously) 5 days/week, for 4 weeks. Swimming consisted 60-min sessions (load 2%), After this period, sciatic nerve extensor digitorum longus (EDL) isolated myographic recordings. Fatigue resistance assessed by percent (%) decline 180 direct tetanic contractions (30 Hz). Safety margin synaptic transmission determined from blockade indirectly evoked twitches (0.5 Hz) induced pancuronium (5 9×10−7 M). EDL muscles also histological histochemical analysis (haematoxylin–eosin (HE); nicotinamide adenine dinucleotide–tetrazolium reductase (NADH-TR)). Significant differences detected two-way ANOVA (p<0.05). did not change body mass, fatigue or kinetic indirect either rats. In contrast, reduced safety (SND=53.3±4.7% vs. S=75.7±2.0%), but affect (SwND=75.81±3.1% Sw=71.0±4.0%). No significant difference type proportions diameters observed any experimental These results indicate that does act as an ergogenic reinforcement weeks On other hand, revealed important toxic effect ND, it reduces animals. Such is masked when associated with physical exercise.