Jumping in aquatic environment after sciatic nerve compression: nociceptive evaluation and morphological characteristics of the soleus muscle of Wistar rats

Abstract

Objective To evaluate the effect of jumping in aquatic environment on nociception and in the soleus muscle of trained and not trained Wistar rats, in the treatment of compressive neuropathy of the sciatic nerve.Methods Twenty-five Wistar rats were distributed into five groups: Control, Lesion, Trained + Lesion, Lesion + Exercise, and Trained + Lesion + Exercise. The training was jumping exercise in water environment for 20 days prior to injury, and treatment after the injury. Nociception was evaluated in two occasions, before injury and seven after injury. On the last day of the experiment, the right soleus muscles were collected, processed and analyzed as to morphology and morphometry.Results In the assessment of nociception in the injury site, the Control Group had higher average than the rest, and the Lesion Group was larger than the Trained + Lesion and Lesion + Exercise Groups. The Control Group showed higher nociceptive threshold in paw, compared to the others. In the morphometric analysis, in relation to Control Group, all the injured groups showed decreased muscle fiber area, and in the Lesion Group was lower than in the Lesion + Exercise Group and Trained + Lesion Group. Considering the diameter of the muscle fiber, the Control Group had a higher average than the Trained + Lesion Group and the Trained + Lesion + Exercise Group; and the Lesion Group showed an average lower than the Trained + Lesion and Lesion + Exercise Groups.Conclusion Resistance exercise produced increased nociception. When performed prior or after nerve damage, it proved effective in avoiding hypotrophy. The combination of the two protocols led to decrease in diameter and area of the muscle fiber.

Analysis of the muscle tissue of Wistar rats submitted to the sciatic nerve compression model and cryotherapy

“…Peripheral nervous injuries directly affect the muscle tissue because they interrupt the neuromuscular communication ( 18 ) and result in loss of function of innervated organ, ( 19 ) and reduction of cross-sectional section and muscle diameter of muscle fibers. ( 20 ) In our study, changes in muscle structure, such as weight reduction, diameter and muscle area were observed in injured groups since 8 th day after surgery, but, when cryotherapy was done, these changes were observed only in 15 th day after surgery, therefore, physiotherapeutic modality reduced speed of muscle atrophy.…”

“…( 24 ) After nervous injury, in addition to described morphological changes, we also observed changes in muscle excitability ( 25 ) and increase in density of conjunctive tissue, ( 24 ) although in experimental models this fact not always occur. ( 20 )…”

Analgesic Effect of Dizocine Combined with Ropivacaine on Recurrent Neuropathic Pain in Peripheral Nerve Compression Rats

“…The evidence suggested that dizocine combined with ropivacaine has a significant analgesic effect in rat model of peripheral nerve compression. Peripheral nerve damage directly affects muscle tissue because they disrupt neuromuscular communication and results in loss of function of the innervating organs and cause muscle fiber cross-section and muscle diameter decrease [15][16][17]. Chronic sciatic nerve compression is characterized by variable degree of degeneration in great myelinated axons and endoneural edema [18,19].…”

Avaliação dos efeitos da natação como reabilitação pós-operatória na regeneração nervosa de ratos da linhagem Wistar submetidos a enxerto de nervos autólogos após lesão do nervo ciático

“…1 Tratamentos não cirúrgicos, como o exercício físico, podem atuar na regeneração nervosa periférica. 4 O exercício físico executado no ambiente aquático induz efeitos fisiológicos que proporcionam benefícios aos sistemas cardiovascular, esquelético, muscular e nervoso que aumentam o processo de reparação tecidual. 6 A natação auxilia na regeneração do nervo ciático em coelhos, 7 peixes 8 e ratos.…”