小剂量MK—801加强100Hz电针抑制大鼠吗啡戒断症状的作用

目的 :观察小剂量MK 80 1(dizocilpine)是否能加强 10 0Hz电针 (electroacupuncture ,EA)抑制大鼠吗啡戒断症状的作用。方法 :大鼠皮下注射递增剂量的吗啡 5天 (每天 3次 ) ,使其对吗啡形成依赖 ,最后一次注射吗啡后 1h ,分别腹腔 (i.p .,0 .0 3mg/kg)或蛛网膜下腔 (i.t.,10 0ng/ 10 μl)注射MK 80 1,注射后 15min给予 10 0HzEA。MK 80 1注射和 10 0HzEA共进行 3次 ,两次之间相隔5h。最后一次EA结束后 30mini.p .纳洛酮 (1mg/kg)催促戒断症状 ,并观察记录 5种戒断症状的表现。结果 :(1)单纯i.p .MK 80 1仅能显著降低直立症状 ;单纯 10 0HzEA能够显著降低直立和振翼样抖动 ;i.p .MK 80 1联合 10 0HzEA能显著降低跳跃、直立、振翼样抖动和体重丢失等 4种戒断症状。 (2 )单纯i.t.MK 80 1能显著降低振翼样抖动 ;i.t .MK 80 1联合EA能显著降低上述四种戒断症状。结论 :小剂量的MK 80 1可加强 10 0HzEA抑制戒断症状的作用 ;联合使用的效果优于单纯应用EA或MK 80 1。

LOW DOSE MK-801 ENHANCES THE EFFECT OF 100Hz ELECTROACUPUNCTURE IN SUPPRESSING MORPHINE WITHDRAWAL SIGNS IN RATS

Objective: To elucidate whether MK 801 at low doses would enhance the effect of 100Hz electroacupuncture (EA) in suppressing morphine withdrawal signs in rats. Methods: Rats were made dependent on morphine by multiple injections of increasing doses of morphine for 5 days. On day 6, an injection of 50 mg/kg morphine was given at 08:00 h. At 09:00 h rats were given intraperitoneal (i.p.) injection (0.03 mg/kg), or intrathecal (i.t.) injection (100 ng) of MK 801, followed by two more injections at an interval of 5 h. 100 Hz EA was administered 15 min after each injection of MK 801. Naloxone (1 mg/kg, i.p.) was given 30 min after the last EA stimulation, and the withdrawal signs were scored for 30 min. Results: (1) Out of 5 naloxone precipitated withdrawal signs one was suppressed by repeated i.p. MK 801 alone; two were suppressed by EA alone; whereas four were suppressed by EA combined with i.p. MK 801. (2) One out of 5 withdrawal signs one was decreased by repeated i.t. MK 801 alone; whereas four were decreased by EA combined with i.t. MK 801. Conclusion: These findings suggest that 100 Hz EA combined with low doses of MK 801 is more effective in suppressing morphine withdrawal signs in rats as compared to the administration of EA or MK 801 alone.