Locomotor training with adjuvant testosterone preserves cancellous bone and promotes muscle plasticity in male rats after severe spinal cord injury.
J Neurosci Res
; 98(5): 843-868, 2020 05.
Article
em En
| MEDLINE
| ID: mdl-31797423
ABSTRACT
Loading and testosterone may influence musculoskeletal recovery after spinal cord injury (SCI). Our objectives were to determine (a) the acute effects of bodyweight-supported treadmill training (TM) on hindlimb cancellous bone microstructure and muscle mass in adult rats after severe contusion SCI and (b) whether longer-term TM with adjuvant testosterone enanthate (TE) delivers musculoskeletal benefit. In Study 1, TM (40 min/day, 5 days/week, beginning 1 week postsurgery) did not prevent SCI-induced hindlimb cancellous bone loss after 3 weeks. In Study 2, TM did not attenuate SCI-induced plantar flexor muscles atrophy nor improve locomotor recovery after 4 weeks. In our main study, SCI produced extensive distal femur and proximal tibia cancellous bone deficits, a deleterious slow-to-fast fiber-type transition in soleus, lower muscle fiber cross-sectional area (fCSA), impaired muscle force production, and levator ani/bulbocavernosus (LABC) muscle atrophy after 8 weeks. TE alone (7.0 mg/week) suppressed bone resorption, attenuated cancellous bone loss, constrained the soleus fiber-type transition, and prevented LABC atrophy. In comparison, TE+TM concomitantly suppressed bone resorption and stimulated bone formation after SCI, produced near-complete cancellous bone preservation, prevented the soleus fiber-type transition, attenuated soleus fCSA atrophy, maintained soleus force production, and increased LABC mass. 75% of SCI+TE+TM animals recovered voluntary over-ground hindlimb stepping, while no SCI and only 20% of SCI+TE animals regained stepping ability. Positive associations between testosterone and locomotor function suggest that TE influenced locomotor recovery. In conclusion, short-term TM alone did not improve bone, muscle, or locomotor recovery in adult rats after severe SCI, while longer-term TE+TM provided more comprehensive musculoskeletal benefit than TE alone.
Palavras-chave
RRID:AB_1157865; RRID:AB_1157897; RRID:AB_138404; RRID:AB_1500896; RRID:AB_2099233; RRID:AB_2147165; RRID:AB_2235587; RRID:AB_2556551; RRID:AB_330924; RRID:AB_60395; RRID:AB_881987; androgen; estradiol; exercise; hypogonadism; neuromuscular plasticity; osteoporosis; physical rehabilitation; regenerative rehabilitation
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Condicionamento Físico Animal
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Traumatismos da Medula Espinal
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Testosterona
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Músculo Esquelético
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Recuperação de Função Fisiológica
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Osso Esponjoso
Limite:
Animals
Idioma:
En
Revista:
J Neurosci Res
Ano de publicação:
2020
Tipo de documento:
Article