反复电针对单发佐剂关节炎模型大鼠脊髓P物质、八肽胆囊收缩素及甲硫氨酸脑啡肽样免疫活性物质自发释放的影响

EFFECT OF REPEATED ELECTROACUPUNCTURE ON SPONTANEOUS RELEASE OF SUBSTANCE P, CHOLECYSTOKININ OCTOPEPTIED AND METHIONINE ENKEPHAL IN IN RATS WITH ADJUVANT MON-ARTHRITIS

有证据表明，反复电针对慢性痛具有累加的治疗作用，机制不明。本文采用完全福民佐剂在大鼠一侧后肢造成单发关节炎模型，分别测定了致炎前及致炎后１～４周大鼠脊髓灌流液中Ｐ物质（ＳＰ）、八肽胆囊收缩素（ＣＣＫ－８）及甲硫氨酸脑啡肽（ＭＥＫ）样免疫活性物质（－ｉｒ）的含量，以及反复的电针刺激对这些神经肽含量的影响。结果如下：（１）正常鼠脊髓灌流液中ＳＰ－ｉｒ含量为１４．９±１．１ｆｍｏｌ／ｍｌ，致炎后第１～４周末脊髓灌流液中ＳＰ－ｉｒ的含量与正常鼠相比无明显差异；每周电针２次的关节炎鼠ＳＰ－ｉｒ的相应含量显著低于不电针的关节炎鼠（ＡＮＯＶＡ，Ｐ＜０．０５），第三周末的测定值也低于正常大鼠（Ｐ＜０．０５）。（２）正常鼠脊髓灌流液中ＣＣＫ８－ｉｒ含量为３９．７±７．１ｆｍｏｌ／ｍｌ：致炎后第１～４周末脊髓灌流液中ＣＣＫ－８－ｉｒ含量显著低于正常鼠（Ｐ＜０．０１），至第四周末接近正常大鼠的水平。（３）正常鼠脊髓灌流液中ＭＥＫ－ｉｒ含量为３２．１±２．３ｆｍｏｌ／ｍｌ；致炎后第１～４周末脊髓灌流液中ＭＥＫ－ｉｒ含量逐渐升高，至第四周末时显著高于正常鼠（Ｐ＜０．０１）：每周电针２次的关节炎鼠ＭＥＫ相应含量至第三周末已显著高于正常?

Repeated electroacupuncture(EA)stimulation was shown to have cumulstivetherapeutic effect on chronic pain.In this article, rats with adjuvant mono-arthritis weregiven EA stimulation twice a week for a toeal of four weeks.The level of substance P(SP),cholecystokinin octopeptide(CCK-8),and methionine enkephalin(MEK)like immunoreactivities(-ir)in the spinal subarachnoid perfusate(CSF)in these animals was determined by radioimmuno assay.The results are as follows:(1)CSF level of SP-ir in arthritic rats 1～4weeks after inoculation were 13.9±0.9,13.4±0.8,16.0±0.8,and 15.5±0. 5 fmol/ml, resdectively, showing no significant difference from that of normal ratS (14. 9±1. 1 fmol/ml). However,rats with repeated EA stimulation displayed significantly lower SP-ir levelduring the same time course(12.9±0.8,12.8±0.7,11.7±1.4,and 15.0±1.3 fmol/ml, respectively)compared with arthritic rats without EA treatmet(ANOVA, P<0.05),andwas even lower than normal control (P<0. 05)after six sessions of EA;(2)CSF level ofCCK-8-ir in arthritic rats 1～4 weeks after inoculation were 18.0±3.2,17.6±3.2,17.0 ±2. 3, and 14. 9 ±2. 2 fmol/ml, respectively, which were significantly lower than normalrats(39.7±7. 1 fmol/ml, P<0.01).Repeated EA brought the CCK-8 concentration to normal. The level was 12. 1±3. 0,16.2±2.2,and 18.1±2.2 fmol/ml after 1～3 weeks(p<0.01,compared with normal rat),and further raised to 31.7±4.4fmol/ml at the end offour weeks, to approach normal level(P>0.05);(3)CSF level of MEK-ir in arthritic ratsraised gradually after inoculation(31.5±1.2,33.5±2.5,and 36.0±2.2 fmol/ml after1～3 weeks),and reached a significantly high level(P<0.01)at the 4th week(39.0±1. 3fmol/ml)as compared with normal rat(32.1±2.3fmol/ml).Repeated EA prompted the increase of MEK-ir concentration to peak at the 3rd week(39.3±1.0),which was significantly higher than normal control level(P<0.05).In conclusion, plastic changes occurredin the spontaneous release of SP-ir,the putative hyperalgesia related neuropeptide,CCK-8-ir,the anti-opioid peptide,and MEK-ir,the endogenous opioid peptide,in the spinal cord afterthe development of adjuvant mono-arthritis. Repeated EA seemed to modify or reverse thepattern of these changes, which may reflect part of the central mechanism or EA's cumulative therapeutic effect on arthritic pain.