摘要
目的 :研究鞘内联合应用吗啡和氯胺酮对神经痛大鼠的作用及对血浆 β 内啡肽水平的影响。方法 :慢性坐骨神经松弛结扎模型大鼠 32只 ,随机分为 4组 ,另 8只健康大鼠做空白对照 (B组 ) ,体重 2 2 0～ 2 6 0 g。C组 (对照组 ) ,鞘内应用 0 .9%生理盐水 10 μl ;K组 (氯胺酮组 ) ,鞘内应用氯胺酮 5 0 μg ;M组 (吗啡组 ) ,鞘内应用吗啡 2 0 μg ;KM组 (吗啡加氯胺酮组 ) ,鞘内应用吗啡 10 μg加氯胺酮 2 5 μg。每日给药一次 ,连续七天。用药后 30min测定热痛阈的变化。用药 7天后取血 2ml,放免法测定血浆 β 内啡肽的含量。结果 :(1)M组和KM组用药前后热痛阈之差均明显高于C组和K组 (P <0 .0 1) ,但随着用药次数的增加 ,M组的镇痛效果逐渐下降 ,在用药后第 6、7天与KM组比较有统计学差异 (P <0 .0 5 )。K组和C组比较在任何时点均有统计学差异 (P <0 .0 1) ;(2 )C组和M组血浆 β 内啡肽水平明显低于B组 (P <0 .0 1)和KM组 (P <0 .0 5 ) ,其它各组间无明显差异。结论 :鞘内应用吗啡加氯胺酮可对抗神经痛大鼠对辐射热的痛觉过敏反应 ,其效果优于单纯应用吗啡和氯胺酮 ,血浆 β 内啡肽水平可在一定程度上反映疼痛的程度。
Objective: To study the effects of intrathecal coadministration of morphine and ketamine on plasma β-endorphin and thermal hyperalgesia of rats with sciatic constriction injury. Methods: Male Wistar rats, weighting 220～260g with a peripheral mononeuropathy produced by placing loosely constrictive ligatures around the common sciatic nerve, were randomly divided into 4 groups (8 animals each group). Another 8 normal rats without any treatment were group B. Group C received intrathecal 0.9% NaCl 10μl, group K ketamine 50μg, group M morphine 20μg, group KM morphine 10μg plus ketamine 25μg. The volume of the injected solution was 10μl, and the catheters were flushed with normal saline 10 μl, once a day for 7 days. Changes in paw withdrawl latency(PWL) to heat stimulus were measured at 30min after injection everyday. Blood (2ml) were obtained form the animals killed after 7days, plasma β-endorphin were measured by radioimmunoassay. Results: (1) The changes in PWL in group KM and M were significantly higher than that in group C and K ( P <0.01),but with time went on, the effect of analgesia in group M was decreased gradually. There were significant differences between group M and group KM on day 6 and 7 ( P <0.05 & P <0.01). Analgesia in group K was significantly higher than that in group C( P <0.01). (2)β-endorphin of the plasma in group C and in group M were significantly lower than that in group B( P <0.01) and in group KM( P <0.05). Conclusion: Morphine plus ketamine administered intrathecally can antagonize thermal hyperalgesia better than morphine or ketamine done. The level of plasma β-endorphin might somehow reflect the intensity of neuropathic pain.
出处
《中国疼痛医学杂志》
CAS
CSCD
2004年第2期110-112,共3页
Chinese Journal of Pain Medicine
