Zhu L, Li C, Ji C, Li W
Institute of Acupuncture and moxibustion, China Academy of Traditional Chinese Medicine, Beijing.
Zhen Ci Yan Jiu. 1993;18(3):214-8.
Our previous work has shown that opiate-like substance (OLS) is involved in the central mechanism of acupuncture analgesia (AA) in the arthritic rats. In this paper, the role of OLS in peripheral mechanism of AA is further studied. Twenty four hours after a subcutaneous injection of Freund's adjuvant into the right ankles, acute arthritis with typical symptoms developed in all the rats. Following needling at Huantiao points for 10 minutes, the pain threshold (PT) was raised by 42.3% (P < 0.05) in the inflamed ankles and by 5.6% in the non-inflamed ones. When systemically administered a dose of 250 and 100 micrograms, naloxone (Nx) could completely and partially (49.6%) block AA respectively. While locally injected a dose of 100 micrograms even 20 micrograms, Nx could completely antagonize AA. After systemic administration of morphine (10, 5.0, 2.5, 1.25 mg/kg), PT rise was dose-related, and PT was raised by 86.5 +/- 22.7% in the affected ankles and by 32.9 +/- 14.9% in the normal ankles at 5 mg/kg in dose. It is evident that the opiate receptors in the inflamed area should by sensitized. These results demonstrate that activation of endogenous opiate system may also be involved in the peripheral AA. Acupuncture may enhance the release of peripheral OLS which can act at the sensitized opiate receptors, leading to more potent analgesic effect in the inflamed area.
我们之前的研究表明，阿片样物质（OLS）参与了关节炎大鼠针刺镇痛（AA）的中枢机制。在本文中，进一步研究了OLS在AA外周机制中的作用。在大鼠右踝关节皮下注射弗氏佐剂24小时后，所有大鼠均出现具有典型症状的急性关节炎。针刺环跳穴10分钟后，炎症踝关节的痛阈（PT）升高了42.3%（P<0.05），非炎症踝关节的痛阈升高了5.6%。当全身给予250微克和100微克剂量的纳洛酮（Nx）时，分别可完全和部分（49.6%）阻断AA。而局部注射100微克甚至20微克剂量的Nx，可完全拮抗AA。全身给予吗啡（10、5.0、2.5、1.25毫克/千克）后，PT升高呈剂量依赖性，在5毫克/千克剂量时，患侧踝关节的PT升高86.5±22.7%，正常踝关节的PT升高32.9±14.9%。显然，炎症区域的阿片受体应该被致敏。这些结果表明，内源性阿片系统的激活也可能参与外周AA。针刺可能增强外周OLS的释放，其可作用于致敏的阿片受体，从而在炎症区域产生更强的镇痛效果。
