Locomotor Treadmill Training Promotes Soleus Trophism by Mammalian Target of Rapamycin Pathway in Paraplegic Rats.
Neurochem Res
; 43(6): 1258-1268, 2018 Jun.
Article
en En
| MEDLINE
| ID: mdl-29737479
ABSTRACT
Assisted-treadmill training, may be helpful in promoting muscle mass preservation after incomplete spinal cord injury (SCI). However, biological mechanism involved in this process is still not fully understood. This study investigated the effects of locomotor treadmill training on muscle trophism mediated by protein kinase B (Akt)/mammalian target of rapamycin (mTOR)/p70 ribosomal protein S6 kinase (p70S6K) in paraplegic rats. Adult female Wistar rats underwent an incomplete thoracic SCI induced by compression using an aneurysm clip. After 7 days, injured animals started a 3-week locomotor treadmill training with body weight-support and manual step help. Soleus trophism was measured by muscle weight and transverse myofiber cross-sectional area (CSA). An enzyme-linked immunosorbent assay (ELISA) and western blot analysis were used to detect brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B (TrkB), Akt, mTOR and p70S6K in paretic soleus. Trained animals did not show locomotor improved, but present an increase in muscle weight and myofiber CSA. Furthermore, the levels of Akt, p70S6K phosphorylation, mTOR and TrkB receptor were increased by training in soleus. In contrast, muscle BDNF levels were significantly reduced after training. The results suggest locomotor treadmill training partially reverts/prevents soleus muscle hypotrophy in rats with SCI. Furthermore, this study provided the first evidence that morphological muscle changes were caused by Akt/mTOR/p70S6K signaling pathway and TrkB up-regulation, which may increase the sensitivity of muscle, reducing autocrine signaling pathway demand of BDNF for cell growth.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Paraplejía
/
Atrofia Muscular
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Músculo Esquelético
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Prueba de Esfuerzo
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Serina-Treonina Quinasas TOR
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Locomoción
Límite:
Animals
Idioma:
En
Revista:
Neurochem Res
Año:
2018
Tipo del documento:
Article
País de afiliación:
Brasil