Whole body vibration accelerates the functional recovery of motor nerve components in sciatic nerve-crush injury model rats

NPD1 Relieves Neuropathic Pain and Accelerates the Recovery of Motor Function After Peripheral Nerve Injury

The incidence of peripheral nerve injury (PNI) in China is continuously increasing. With an inability to function due to sensory and motor abnormalities, patients with PNI suffer from neuropathic pain and subsequent lesions. Presently, effective treatments for PNI are limited. To determine the role of neuroprotectin D1 (NPD1) in PNI, a sciatic nerve crush injury model was developed to investigate the impact of NPD1 on sensory and motor function recovery following nerve injury. The results demonstrated that NPD1 administered at different time points might reduce mechanical allodynia and thermal hyperalgesia caused by PNI, and its analgesic effect was not tolerated. Immunohistochemistry analyses revealed that administering NPD1 to PNI mice decreased the spinal microglia and astrocyte activation and decreased the inflammatory factor expression in the spinal dorsal horn. Furthermore, NPD1 can inhibit the invasion of IBA-1+ macrophages in dorsal root ganglions generated by nerve injury. Meanwhile, it can help rehabilitate motor and neuromuscular functions following PNI. The results indicate that NPD1 may be involved in the sensory and motor function recovery following PNI.

Adenosine A2A Receptor Agonist, Polydeoxyribonucleotide Treatment Improves Locomotor Function and Thermal Hyperalgesia Following Neuropathic Pain in Rats

PURPOSE

Lithotomy position has been widely used in the various urologic surgery. Occasionally sensory and motor problems of the lower extremities are occurred due to the lithotomy position and these deficits may be related with sciatic nerve injury (SNI). Inflammatory process is a factor to induce functional impairment after SNI. Therefore, we evaluated the role of adenosine A2A receptor agonists, polydeoxyribonucleotide (PDRN) showing anti-inflammatory effect on locomotor function following SNI in rats.

METHODS

Sciatic nerve was compressed with surgical clips for 1 minute after exposing of right sciatic nerve. After 3 days of SNI, PDRN (2, 4, and 8 mg/kg) was applied to the damaged area of sciatic nerve once daily for 10 days. Walking track analysis was conducted for locomotor function and plantar test was performed for thermal pain sensitivity. Level of cyclic adenosine-3´,5´-monophosphate (cAMP) were measured using enzyme-linked immunosorbent assay. Western blot analysis was performed for tumor necrosis factor (TNF)-α, interleukin (IL)-1β, cAMP response element binding protein (CREP), vascular endothelial growth factor (VEGF). Immunofluorescence for neurofilament was also conducted.

RESULTS

Locomotor function was decreased and thermal pain sensitivity was increased by SNI. SNI enhanced proinflammatory cytokines' production, such as TNF-α and IL-1β, while suppressed CREP phosphorylation and cAMP level. SNI also reduced the expression of VEGF and neurofilaments. However, treatment with PDRN inhibited proinflammatory cytokines' production and upregulated CREP phosphorylation and cAMP expression. PDRN also enhanced the expression of VEGF and neurofilaments. As a result, PDRN improved locomotor function and alleviated thermal hyperalgesia after SNI.

CONCLUSION

PDRN has shown potential to be used as an effective treatment for neuropathic pain.