Graduate Institute of Acupuncture Science, China Medical University, Taichung 40402, Taiwan.
Evid Based Complement Alternat Med. 2013;2013:319124. doi: 10.1155/2013/319124. Epub 2013 Jun 25.
The present study was undertaken to investigate the influence of electroacupuncture (EA) on compulsive scratching in mice and c-Fos expression elicited by subcutaneous (s.c.) administration of a known puritogen, 5'-guanidinonaltrindole (GNTI) to the neck. Application of EA to Hegu (LI4) and Quchi (LI11) acupoints at 2 Hz, but not 100 Hz, attenuated GNTI-evoked scratching. In mice pretreated with the µ opioid receptor antagonist naloxone, EA 2 Hz did not attenuate GNTI-evoked scratching, whereas EA at 2 Hz did attenuate GNTI-evoked scratching in mice pretreated with the κ opioid receptor antagonist nor-binaltorphimine. Moreover, intradermal (i.d.) administration of the selective µ opioid receptor agonist [d-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin acetate (DAMGO) attenuated GNTI-evoked scratching behavior, while s.c. administration of DAMGO was ineffective. GNTI provoked c-Fos expression on the lateral side of the superficial layer of the dorsal horn of the cervical spinal cord. Application of 2 Hz EA to LI4 and LI11 decreased the number of c-Fos positive nuclei induced by GNTI. It may be concluded that application of 2 Hz EA to LI4 and LI11 attenuates scratching behavior induced by GNTI in mice and that the peripheral µ opioid system is involved, at least in part, in the anti-pruritic effects of EA.
本研究旨在探讨电针对颈部皮下给予已知致痒原 5'-胍基-N-亚硝基吲哚（GNTI）后引起的强迫性抓挠行为和 c-Fos 表达的影响。2 Hz 的电针对合谷（LI4）和曲池（LI11）穴位的应用可减弱 GNTI 诱发的抓挠，而 100 Hz 的电针则没有这种作用。在预先给予 μ 阿片受体拮抗剂纳洛酮的小鼠中，2 Hz 的电针不能减弱 GNTI 诱发的抓挠，而在预先给予 κ 阿片受体拮抗剂 nor-binaltorphimine 的小鼠中，2 Hz 的电针则可减弱 GNTI 诱发的抓挠。此外，皮内（i.d.）给予选择性 μ 阿片受体激动剂 [d-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin acetate（DAMGO）可减弱 GNTI 诱发的抓挠行为，而 DAMGO 皮下注射则无效。GNTI 引起颈脊髓背角浅层外侧的 c-Fos 表达。2 Hz 的电针应用于 LI4 和 LI11 可减少 GNTI 诱导的 c-Fos 阳性核数。由此可以得出结论，2 Hz 的电针应用于 LI4 和 LI11 可减弱 GNTI 诱导的小鼠抓挠行为，外周 μ 阿片系统至少部分参与了电针的止痒作用。
