Analgesic effects of melatonin on post-herpetic neuralgia

作者:Deng, Yun-Kun; Ding, Ji-Fei; Liu, Jin*; Yang, Yong-Yao
来源:International Journal of Clinical and Experimental Medicine, 2015, 8(4): 5004-5009.

摘要

Objective: This study aims to explore the analgesic effects of melatonin on post-herpetic neuralgia and its possible mechanism. Methods: A total of 48 PHN Wistar rats were divided into 4 groups randomly: Normal, PHN, PHN+MT and naloxone, 4P-PDOT or L-arginine+120 mg/kg MT (C). Heat pain latency was determined after MT injection for 20 min, 40 min, 80 min and 120 min respectively. The expression levels of delta receptor and MT2 receptor in different tissues of rats were detected by RT-PCR method. NO content was determined. Results: Heat pain latency in PHN rats were lower than that of control group (P<0.05), MT could increase the heat pain latency with dose-dependent, while naloxone, 4P-PDOT and L-arginine could reverse the analgesic effect of MT (P<0.05). The expression levels of d receptor and MT2 receptor in spinal cord, hypothalamus and hippocampus in PHN+MT (120 mg/kg, i. p.) group were significantly higher than that of PHN group ( P<0.05). The NO levels in the brain and spinal cord tissues in PHN group were higher than that of PHN+MT (120 mg/kg) group (P<0.05). Conclusions: MT had significant analgesic effects in the treatment of PHN, and its mechanism was closely related with delta opioid receptor, NO and MT2 receptor.