Fan Yu, Kim Do-Hee, Ryu Yeonhee, Chang Suchan, Lee Bong Hyo, Yang Chae Ha, Kim Hee Young
Department of Physiology, College of Korean Medicine, Daegu Haany University, Daegu, South Korea.
Korean Medicine Fundamental Research Division, Korea Institute of Oriental Medicine, Daejeon, South Korea.
Front Neurosci. 2018 Dec 12;12:907. doi: 10.3389/fnins.2018.00907. eCollection 2018.
Electrical skin measurements at acupuncture points (acupoints) have been utilized as a diagnostic and therapeutic aid for more than 50 years. Although acupoints are described as having distinct electrical properties, such as high conductance and low impedance, the underlying mechanisms are currently unknown. The present study investigated in a rat model of hypertension whether the high conductance at acupoints is a result of the release of the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) during neurogenic inflammation in the referred pain area. When plasma extravasation from neurogenic inflammation was examined by exploring the leakage of intravenously injected Evans blue dye (EBD) to the skin, extravasated EBD was found most frequently in acupoints on the wrist. The increased conductance and temperature at these acupoints occurred during the development of hypertension. The increase in conductance and plasma extravasation at acupoints in hypertensive rats was ablated by cutting median and ulnar nerves, blocking small diameter afferent fibers with resiniferatoxin (RTX) injection into median and ulnar nerves, or antagonizing SP or CGRP receptors in acupoints. In turn, intradermal injection of SP or CGRP resulted in increased conductance and plasma extravasation in naïve rats. Elevated levels of SP and CGRP were found in the acupoints of hypertensive rats. These findings suggest that the high conductance at acupoints is due to vascular leakage following local release of SP and CGRP during neurogenic inflammation.
针刺穴位的皮肤电测量作为一种诊断和治疗辅助手段已被应用五十多年。尽管穴位被描述为具有独特的电学特性，如高电导和低阻抗，但其潜在机制目前尚不清楚。本研究在高血压大鼠模型中探究了穴位的高电导是否是由于神经源性炎症时在牵涉痛区域释放神经肽P物质（SP）和降钙素基因相关肽（CGRP）所致。通过检测静脉注射伊文思蓝染料（EBD）向皮肤的渗漏情况来检查神经源性炎症引起的血浆外渗，发现腕部穴位处EBD外渗最为常见。这些穴位的电导和温度升高发生在高血压发展过程中。切断正中神经和尺神经、向正中神经和尺神经注射树脂毒素（RTX）阻断小直径传入纤维或拮抗穴位中的SP或CGRP受体，均可消除高血压大鼠穴位处的电导增加和血浆外渗。反过来，在未处理的大鼠中皮内注射SP或CGRP会导致电导增加和血浆外渗。在高血压大鼠的穴位中发现SP和CGRP水平升高。这些发现表明，穴位的高电导是由于神经源性炎症时局部释放SP和CGRP后血管渗漏所致。
