鞘内泵入吗啡对炎性疼痛大鼠T淋巴细胞亚群及NK细胞表型的影响

EFFECT OF INTRATHECAL PUMPING MORPHINE ON T LYMPHOCYTE SUBSETS AND NK CELL PHENOTYPE IN RATS WITH FORMALIN PAIN

目的:观察鞘内泵入不同剂量的吗啡对福尔马林炎性疼痛大鼠免疫功能的影响。方法:40只雄性SD大鼠随机分为生理盐水对照组(NS组)、假手术组(F组)和吗啡组(M组),其中M组分为10μg.h-1(M1)、5μg.h-1(M2)、2.5μg.h-1(M3)三种不同剂量组,采用改良Yaksh法进行鞘内置管,Alzet泵持续泵入吗啡或生理盐水1天后,构建福尔马林炎性疼痛模型,根据疼痛加权评分(PIS)评价吗啡镇痛效应,持续泵入7天后分离脾脏单个核细胞进行培养,流式细胞仪检测脾脏T淋巴细胞亚群和NK细胞表型变化。结果:(1)与NS组比较,M1、M2、M3组在福尔马林炎性疼痛第一时相和第二时相的PIS有显著性差异(P<0.01),随着泵入剂量的增加,PIS逐渐下降,但三者间比较无显著性差异(P>0.05);(2)与NS组比较,吗啡泵入7天后M1、M2、M3组可导致CD3+、CD3+CD4+、CD3+CD8+数量及百分率降低,CD4+/CD8+降低,CD161+数量及百分率降低,有显著性差异(P<0.05)。结论:(1)鞘内泵入吗啡(2.5μg.h-1)对炎性疼痛大鼠具有明显的抗伤害作用;(2)鞘内泵入不同剂量吗啡(10μg.h-1、5μg.h-1、2.5μg.h-1)可剂量依赖性地抑制大鼠细胞免疫功能。

Objective： To evaluate the effect of intrathecal pumping different dosage of morphine on cellmediated immunity. Methods：Forty male Sprague-Dawley rats were randomly divided into 5 groups（ n = 8 in each group） ： saline group （ NS ）, sham control group and morphine groups ： M 1 group （ 10μg · h ^- 1 ） , M2 group （5μg · h^-1 ） ,M3 group （2.5μg · h^-1 ）. Rats were anesthetized with 10% chloral hydrate （300-350）mg · kg^-1. A microspinal catheter was inserted into the lumbar subarachnoid space. After five days,an Alzet osmotic minipump was connected to a polyurethane catheter. 5% formalin（50μl） was injected s.c. into plantar surface of the left hindpaw of the rats. Pain intensity scores （PIS） was utilized to assess the antinociceptive effect of morphine. Spleens were aseptically removed to obtain splenic cells then phenotypic expression of cell surface markers of T lymphocyte subsets （ CD3 ^＋ , CD3 ^＋ CD4 ^＋ , CD3 ^＋ CD8^＋ ,CD4^＋/CD8^＋） and NK cells （CD161 ^＋） were analyzed by flow cytometry. Results： （1） Compared with NS group, the PIS of morphine groups＇markedly decreased （P 〈0.01 ） in the first and second phase of formalin pain with a dose-dependent pattern ; （2） Phenotypic expression of T lymphocyte subsets and NK cells assessed by flow cytometry were different between NS group and all morphine groups. Conclusion ： （ 1 ） Intrathecal pumping morphine （ 2.5 μg · h^ - 1 ） has significant antinociceptive effect ; （ 2 ） Morphine can suppress immune function in rats with formalin pain.