الفهرس | Only 14 pages are availabe for public view |
Abstract Background: Nandrolone decanoate is one of androgenic anabolic steroids (AAS). It is used by athletes in supraphysiological doses to enhance muscle performance. Recently, researches reported that training produced beneficial dynamic changes in skeletal muscles in contrary to AAS. Aim of the work: to investigate the local effect of nandrolone on the structure of the skeletal muscle of rats subjected to physical exercise. Materials and methods: Forty-two adult male albino rats of average weight 150-200 gms were divided into five groups, group I: a control group, group II: rats were injected in the right gastrocnemius muscle with nandrolone (5mg/kg twice weekly for six weeks), group III: a training group that performed a specified training program (swimming 5 days/week for six weeks), group IV: a steroid and training group that were injected with nandrolone and performed the training program and group V: a Recovery group that were treated as group IV but the rats were left to recover for four weeks. The right gastrocnemius muscles were dissected out and processed for light and electron microscopic examination. Morphometric measurements and statistical analysis were performed. Results: Splitting of the muscle fibers, mononuclear cellular infiltration, congested blood vessels and significant increase in the interstitial tissue collagen were observed in rats of both groups II and IV. Separation between the myofibrils, loss of 2 myofilaments, dilated cisternae of sER, distorted sarcomeres with disruption of the Z lines and mitochondrial damage were detected in both groups. In rats of group III there was significant muscle fiber hypertrophy, increased glycogen content and decreased interstitial tissue collagen. By EM, their myofibrils showed regular sarcomeres with an apparent increase in the number of mitochondria. Most of the fibers of recovery group were nearly similar to the control group. Conclusion: Nandrolone induced reversible degenerative changes in the muscle fibers. Physical exercise could minimize the harmful effect of nandrolone on the structure of the skeletal muscle. Keywords: Anabolic steroids, physical exercise, skeletal muscle, albino rat. |