Effects of pulsed electromagnetic field and swimming exercise on rats with experimental sciatic nerve injury

Effect and mechanism of Tetramethylpyrazine in repair of sciatic nerve injury in rats

OBJECTIVE

Observing the effects of Tetramethylpyrazine (TMP) on the expression of Collagen IV and Laminin in neurovascular basement membrane and the apoptosis of vascular endothelial cells, and to study the mechanism of TMP in the treatment of sciatic nerve injury.

RESULTS

Compared with the NS group, the TMP group had a significant increase in the sciatic nerve function index (P < 0.01).The miss times in TMP group was significantly lower than that in NS group (P < 0.01). The HE staining results of the TMP group showed irregular arrangement of some neuronal axons and Schwann cells, and more edema and rupture of cells. The proliferation of glial cells and inflammatory cells was significantly increased in TMP group. The results of immunohistochemistry showed that the expression of type IV collagen and laminin in the TMP group group was distributed around the blood vessels, vascular endothelial cells, basal membrane and glial cells after SNI. The expression of type IV collagen and laminin in TMP group increased significantly(P < 0.05). Immunofluorescence showed that compared with NS group, the apoptosis rate of TMP group was significantly decreased (P < 0.01). Flow cytometry results showed that compared with the NS group, the number of CECs in the TMP group was significantly decreased (P < 0.01).

CONCLUSIONS

TMP can effectively improve the sciatic nerve functional index (SFI) of Sprague Dawley (SD) rats, enhance the proliferation of sciatic nerve vascular endothelial cells, reduce apoptosis, promote the expression of Collagen IV and Laminin in sciatic nerve microvascular basal membrane components, thereby promoting angiogenesis and improving lower limb function in rats.

Physical exercise to promote regeneration after peripheral nerve injury in animal models: A systematic review

Peripheral nerve injuries are common injuries that often have a drastic effect on patient's activities of daily living and physical function. While techniques for the surgical repair of these injuries have improved over time, rehabilitation methods following these repairs have been non-standardized and under researched. Electronic searches were conducted in Ovid/Medline and SCOPUS to identify articles that discuss rehabilitation and exercise following peripheral nerve injury in animal models and its effects on peripheral nerve regeneration and recovery of function. Thirty-eight articles met inclusion criteria; all were prospective studies in animal models. This systematic review suggests that exercise is a useful tool in returning autonomy to the individual and has beneficial effects in the recovery from peripheral nerve injury. It is beneficial to use rehabilitation exercises following the repair of peripheral nerve injuries to promote regeneration, and timing of that exercise may be just as important as the exercise prescribed. However, further studies with standardized models and outcome measures need to be conducted before translation to clinical trials.

Assessment of the Effects of Swimming as a Postoperative Rehabilitation on Nerve Regeneration of Wistar Rats Submitted to Grafting of Autologous Nerves after Injury to the Sciatic Nerve

Objective  To evaluate the effects of swimming on nerve regeneration after sciatic nerve injury in Wistar rats. Methods  A total of 30 Wistar rats was divided into 3 groups: Sham + Nat group animals that were not submitted to graft surgery and were submitted to swimming ( n  = 10); Graft group: animals submitted to autologous sciatic nerve graft ( n  = 10); and Graft + Nat group: animals submitted to autologous sciatic nerve graft surgery and to swimming ( n  = 10). The results were analyzed on the software (GraphPad Software, San Diego, CA, USA). Results  In the first evaluation, all sciatic functional index (SFI) values were similar ( p  = 0.609). Thirty days after the surgical procedure, we observed differences between all the comparisons: Sham + Nat (-34.64 ± 13.89) versus Graft (-145.9 ± 26.06); Sham + Nat versus Graft + Nat (-89.40 ± 7.501); Graft (-145.9 ± 26.06) versus Graft + Nat (-89.40 ± 7.501). In the measurements (60 and 90 days), there was no statistical difference between the Graft and Graft + Nat groups, with significantly lower values in relation to the control group ( p  < 0.001). The number of motor neurons presented differences in the comparisons between the Sham + Nat and Graft groups (647.1 ± 16.42 versus 563.4 ± 8.07; p  < 0.05), and between the Sham + Nat and Graft + Nat groups (647.1 ± 16.42 versus 558.8 ± 14.79; p  < 0.05). There was no difference between the Graft and Graft + Nat groups. Conclusion  Animals submitted to the swimming protocol after the sciatic nerve grafting procedure did not present differences in the SFI values and motor neuron numbers when compared to the control group. Therefore, this type of protocol is not efficient for the rehabilitation of peripheral nerve lesions that require grafting. Therefore, further studies are needed.

Effects of swimming exercise on nerve regeneration in a rat sciatic nerve transection model

Background: Swimming is commonly considered to be an efficient rehabilitation exercise to treat peripheral nerve injury. However, the most effective resistance level and exercise duration is still unclear. We investigated the effects and mechanisms of swimming at various exertion levels in a rat sciatic nerve transection model.

Methods: Sciatic nerve transection rats were randomized into the following four groups based on swimming duration (from the 7th day to the 28th day post-surgery): sedentary control group (SC), S10 group (10 min/3 times/week), S20 group (20 min/3 times/week), and S30 group (30 min/3 times/week) (n = 10 each). Axon regeneration, electrophysiological properties, muscular weights, macrophage infiltration, and nerve repair associated maker, calcitonin gene-related peptide (CGRP), were measured.

Results: Dramatic higher successful percentages of nerve regeneration across the 10-mm gaps in swimming groups compared to the SC group. Total area of nerve regeneration significantly improved in the S10 group; however, electrophysiological properties, muscular weights, and macrophage infiltration in the regenerated nerves of rats did not differ significantly between the various exercise groups. CGRP expression was significantly increased in the spinal cord of rats in the S20 group.

Conclusions: Our data indicated that CGRP-related axonal regeneration improved significantly with moderate swimming. These results should inspire new studies in physiotherapeutic practice for related human treatment.

The effect of weight-bearing exercise and non-weight-bearing exercise on gait in rats with sciatic nerve crush injury

[Purpose] The purpose of this study was to access the effect of weight bearing exercise (treadmill exercise) and non-weight-bearing exercise (swimming exercise) on gait in the recovery process after a sciatic nerve crush injury. [Subjects and Methods] Rats were randomly divided into a swimming group (n=3) with non-weight-bearing exercise after a sciatic nerve crush and a treadmill group (n=3) with weight bearing exercise after a sciatic nerve crush. Dartfish is a program that can analyze and interpret motion through video images. The knee lateral epicondyle, lateral malleolus, and metatarsophalangeal joint of the fifth toe were marked by black dots before recording. [Results] There were significant differences in TOK (knee angle toe off) and ICK (knee angle at initial contact) in the swimming group and in TOK, ICA (ankle angle at initial contact), and ICK in the treadmill group. In comparison between groups, there were significant differences in TOA (ankle angle in toe off) and ICA at the 7th day. [Conclusion] There was no difference between weight bearing and non-weight-bearing exercise in sciatic nerve damage, and both exercises accelerated the recovery process in this study.