小鼠低频和高频电针镇痛阿片机制的探讨

探讨小鼠低频和高频电针镇痛的阿片机制。方法：采用交叉耐受和受体药理学方法，以甩尾潜伏期增加的百发数作为评判电针镇痛效果的指标。结果：（１）吗啡镇痛与２Ｈｚ电针镇痛之间存在交叉耐受。（２）２／１００Ｈｚ电针镇痛分别与２Ｈｚ、１００Ｈｚ电针镇痛存在交叉耐受；而２Ｈｚ电针镇痛与１００Ｈｚ电针镇痛不存在交叉耐受。（３）ＣＣＫ受体拮抗剂Ｌ３６５，２６０可显著加强１００Ｈｚ电针镇痛效应，对２Ｈｚ电针镇痛无明显

STUDY FOR THE OPIOID MECHANISMS UND ERLYING THE ANALGESIC EFFECT INDUCED BY HIGH-VERSUS LOW-FREQUENCY ELECTROACUPUNCTURE IN MICE

Objective: To study the opioid mechanisms of the analgesia induced by high versus low frequency electroacupuncture (EA) in mice. Methods: Cross tolerance technique and receptor pharmacological methods were used. The percentage increase in tail flick latency (TFL) was taken to assess the efficacy of EA analgesia. Results: (1) Mice made tolerant to morphine showed a cross tolerance to 2 Hz EA analgesia (EAA). (2) Mice made tolerant to 2/100 Hz EA showed cross tolerance to both 2 Hz and 100 Hz EAA, whereas 2 Hz EAA showed no cross tolerance to 100 Hz EAA. (3) Subcutaneous (s.c.) injection of CCK B receptor antagonist L365,260 produced a marked potentiation of the analgesia induced by 100 Hz EA, but not 2 Hz EA, and a significant reversal of acute or chronic tolerance to 100 Hz EA. Conclusion: (1) Low and high frequency EAA in mice are mediated by different types of opioid receptors. (2) Endogenous CCK 8 shows an antagonistic effect on 100 Hz EAA, but not 2 Hz EAA, and CCK is involved in 100Hz induced tolerance. (3) The opioid and CCK mechanisms underlying EA analgesia seem to be similar in rats and in mice. Key words Electroacupuncture;Analgesia;Tolerance;Morphine;Opioid receptor;Cholecytokinin octapeptide (CCK 8)nce rates were 84.7% and 89.7%, respectively. The adverse reactions of the two drugs, mainly skin rashes, were mild and transient, the incidences were 7.0% and 4.3% respectively. The differences between the two groups were all not statistical significant ( P >0.05). We can conclude from this study that the efficacy and safety of cefpiramide 2~4g per day for 7~14 days were comparable with those of cefoperazone in the treatment of common bacterial infections.