Endurance and resistance exercise training programs elicit specific effects on sciatic nerve regeneration after experimental traumatic lesion in rats.
OBJECTIVE
To evaluate the effects of endurance, resistance, and a combination of both types of exercise training on hindlimb motor function recovery and nerve regeneration after experimental sciatic nerve lesion in rats.


METHODS
Sciatic nerve crush was performed on adult male rats, and after 2 weeks of the nerve lesion, the animals were submitted to endurance, resistance, and a combination of endurance-resistance training programs for 5 weeks. Over the training period, functional recovery was monitored weekly using the Sciatic Functional Index (SFI) and histological and morphometric nerve analyses were used to assess the nerve regeneration at the end of the trainings.


RESULTS
The SFI values of the endurance-trained group reached the control values from the first posttraining week and were significantly better than both the resistance-trained group at the first, second, and third posttraining weeks and the concurrent training group at the first posttraining week. At the distal portion of the regenerating sciatic nerve, the endurance-trained group showed a greater degree of the myelinated fiber maturation than the sedentary, resistance-trained, and concurrent training groups. Furthermore, the endurance-trained group showed a smaller percentage area of endoneurial connective tissue and a greater percentage area of myelinated fibers than the sedentary group.


CONCLUSIONS
These data provide evidence that endurance training improves sciatic nerve regeneration after an experimental traumatic injury and that resistance training or the combination of 2 strategies may delay functional recovery and do not alter sciatic nerve fiber regeneration.
Ilha
Jocemar
J
Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, RS, Brazil.
Araujo
Rafaela T
RT
Malysz
Tais
T
Hermel
Erica E S
EE
Rigon
Paula
P
Xavier
Léder L
LL
Achaval
Matilde
M
D000818:Animals; D004195:Disease Models, Animal; D005081:Exercise Therapy / Q000295:instrumentation / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology; D020439:Growth Cones / Q000502:physiology / Q000648:ultrastructure; D006614:Hindlimb / Q000294:innervation / Q000503:physiopathology; D007794:Lameness, Animal / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology; D009413:Nerve Fibers, Myelinated / Q000502:physiology / Q000648:ultrastructure; D009416:Nerve Regeneration / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function / Q000502:physiology; D012584:Sciatic Nerve / Q000166:cytology / Q000293:injuries* / Q000502:physiology*; D020426:Sciatic Neuropathy / Q000473:pathology / Q000503:physiopathology* / Q000534:rehabilitation*