针刺镇痛是针灸疗法中应用最为广泛的领域。以往关于针刺镇痛的实验研究多数将焦点放在中枢（脊髓和脑），而对外周局部病灶处关注不多。皮肤作为人体最大的神经内分泌免疫器官，能合成和分泌多种神经递质，包括一些与炎症和疼痛都密切相关的物质，如神经生长因子（NGF）和多种伤害性神经肽类物质。因此本研究从针刺对疼痛局部病灶的影响出发，以疼痛局部病灶皮肤为研究对象，采用行为学、免疫组化、Western blot及RT-PCR等技术观察了佐剂性炎症（CFA）痛大鼠和电针干预后大鼠痛行为、病灶局部皮肤NGF和TrkA受体蛋白和基因表达、皮肤P-物质（SP）和降钙素基因相关肽（CGRP）表达，皮肤交感神经纤维(VMAT-2-IR)和肽能神经纤维(CGRP-IR)的密度和出芽，从电针调节皮肤NGF/TrkA信号出发，进而影响到病灶皮肤中某些伤害性神经肽的释放以及相关神经纤维可塑性的过程来揭示针刺镇痛的局部作用机制。

Acupuncture analgesia is the most widely used field in acupuncture and moxibustion therapy. Most of the previous experimental studies on acupuncture analgesia focused on the central nerve system (spinal cord and brain), little payed attention to the peripheral local lesions. Skin is the largest neuroendocrine immune organ in the body. It can synthesize and secrete multiple neurotransmitters including NGF and several noxious neuropeptides which are correlated with both inflammation and pain. Taking the peripheral skin as the sole object of study, in rats after CFA and electroacupuncture treatment, we investigated the pain response, local NGF and TrkA receptor protein and their mRNA expression, SP and CGRP expression, and density and sprouting of sympathetic nerve fiber (VMAT-2-IR) and peptide nerve fiber (CGRP-IR) by using behavior, immunohistochemistry, western blot and RT-PCR. The local analgesic mechanism of electroacupuncture could be revealed by its effect on NGF/TrkA signal of skin and succedent effect on release of some noxious neuropeptide and the plasticity of relevant nerve fibers.