Mojarad Negin, Janzadeh Atousa, Yousefifard Mahmoud, Nasirinezhad Farinaz
Physiology Research Center and Department of Physiology, Faculty of Medicine, International Campus, Iran University of Medical Sciences, Tehran, Iran.
Physiology Research Center and Department of Physiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
J Chem Neuroanat. 2018 Jan;87:60-70. doi: 10.1016/j.jchemneu.2017.04.005. Epub 2017 Apr 18.
The effect of Low Level Laser Therapy (LLLT) as a non-invasive treatment of spinal cord injury (SCI) is still under investigation. Therefore, the present study aimed to evaluate the effectiveness of LLLT on neuropathic pain and interleukin-6 (IL-6) expression following SCI in male rats.
46 adult male rats were divided into 5 groups of control, SCI, treatment with methylprednisolone sodium succinate (MPSS), 1-week LLLT and 2-week LLLT. Animals underwent behavioral evaluations for motor behavior, level of allodynia and hyperalgesia every week. At the end, spinal cord was extracted and IL-6 level was assessed by ELISA method.
Treatment with MPSS and 2-week LLLT had led to motor function recovery (df: 24, 145; F=223.5; p <0.001). SCI did not affect mechanical (df: 24, 145; F=0.5; p=0.09), and cold allodynia (df: 24, 145; F=0.3; p=0.17) but significantly increased mechanical (df: 24, 145; F=21.4; p<0.001) and heat hyperalgesia (df: 24, 145; F=16.1; p<0.001). Treatment with MPSS and 1 and 2-weeks LLLT improved mechanical hyperalgesia (p<0.05) and heat hyperalgesia (p<0.01). The increased level of IL-6 following SCI was also compensated by administration of MPSS or LLLT (df: 4, 10; F=8.74; p=0.003).
Findings show that long periods of LLLT have better effects in improving the complication of SCI. In summation, since LLLT does not cause the side effects of MPSS, long-term use of LLLT may be a proper alternative for MPSS in decreasing post SCI side effects.
低强度激光疗法（LLLT）作为脊髓损伤（SCI）的一种非侵入性治疗方法，其效果仍在研究中。因此，本研究旨在评估LLLT对雄性大鼠脊髓损伤后神经性疼痛和白细胞介素-6（IL-6）表达的有效性。
将46只成年雄性大鼠分为5组，即对照组、脊髓损伤组、琥珀酸钠甲泼尼龙（MPSS）治疗组、1周LLLT治疗组和2周LLLT治疗组。每周对动物进行运动行为、痛觉过敏和痛觉超敏水平的行为评估。最后，提取脊髓并通过ELISA法评估IL-6水平。
MPSS治疗和2周LLLT治疗导致运动功能恢复（自由度：24, 145；F = 223.5；p < 0.001）。脊髓损伤未影响机械性（自由度：24, 145；F = 0.5；p = 0.09）和冷痛觉过敏（自由度：24, 145；F = 0.3；p = 0.17），但显著增加了机械性（自由度：24, 145；F = 21.4；p < 0.001）和热痛觉超敏（自由度：24, 145；F = 16.1；p < 0.001）。MPSS治疗以及1周和2周LLLT治疗改善了机械性痛觉超敏（p < 0.05）和热痛觉超敏（p < 0.01）。脊髓损伤后IL-6水平的升高也通过给予MPSS或LLLT得到了补偿（自由度：4, 10；F = 8.74；p = 0.003）。
研究结果表明，长时间的LLLT在改善脊髓损伤并发症方面具有更好的效果。总之，由于LLLT不会引起MPSS的副作用，长期使用LLLT可能是MPSS在减少脊髓损伤后副作用方面的合适替代方法。
