鞘内注射纳洛酮对术后痛大鼠IFN-γ表达的影响

Effect of intrathecal injection of naloxone on IFN-γ expression in rats with postoperative pain

目的:观察鞘内注射不同剂量纳洛酮对术后痛大鼠干扰素-γ(interferon,IFN-γ)表达的影响。方法:采用SPF级健康雄性SD大鼠行鞘内置管造模,将造模成功的144只大鼠按随机数字表法分为6组(n=24):生理盐水组(C组)、术后痛组(P组)、小剂量纳洛酮组(N1组,1 ng/kg)、大剂量纳洛酮组(N2组,100 ng/kg)、术后痛+小剂量纳洛酮组(PN1组,1 ng/kg)和术后痛+大剂量纳洛酮组(PN2组,100 ng/kg)。P组、PN1和PN2组于右足跖肌切口制备术后痛模型。各组于鞘内给药前24 h (T_(0))、给药1 h (T_(1))、6 h (T_(2))、24 h (T_(3))、48 h (T_(4))、72 h (T_(5))检测机械缩足反射阈值(mechanical withdrawal threshold,MWT)和热缩足反射潜伏期(thermal withdrawal latency,TWL)。各组在T_(0)、T_(2)、T_(3)、T_(5)分别取6只大鼠处死,取海马、外周血(血浆),以ELISA法检测IFN-γ浓度。结果:术后痛模型可引起大鼠血浆IFN-γ水平显著降低,随着痛阈的恢复,IFN-γ水平逐渐接近生理状态。单纯小剂量纳洛酮鞘内给药6 h内,与生理盐水组相比IFN-γ水平轻度增高。大剂量纳洛酮在给药后24 h内,与生理盐水组相比IFN-γ水平轻度降低;小剂量纳洛酮可减弱术后痛引发的IFN-γ水平降低,大剂量纳洛酮可增强术后痛导致的IFN-γ水平降低。结论:鞘内注射不同剂量纳洛酮可影响术后痛大鼠血浆IFN-γ的表达,进而参与机体免疫调节,而海马IFN-γ水平在上述干预条件下始终维持稳定。

Objective:To observe the effect of intrathecal naloxone given of different doses on IFN-γexpression in rats with postoperative pain.Methods:One hundred and forty-four healthy male rats,were successfully catheterized and randomly divided into 6 groups (n=24):saline group (C),postoperative pain group (P),low-dose naloxone group (N1,1 ng/kg),high-dose naloxone group (N2,100 ng/kg),postoperative pain+lowdose naloxone group (PN1,1 ng/kg),postoperative pain+high-dose naloxone group (PN2,100 ng/kg)rats.Postoperative pain models were established with right plantar muscle incision in group P,group PN1and group PN2.Both mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL)were measured for each group at 6 separate time points:24 h before intrathecal administration (T_(0)),1 h (T_(1)),6 h (T_(2)),24h (T_(3)),48 h (T_(4)) and 72 h (T_(5)) after intrathecal administration.Six rats from each time point (T_(0),T_(2),T_(3),T_(5)) were decapitalized.Hippocampus and plasma were harvested for IFN-γmeasurement via ELISA.Results:Postoperative pain caused a significant decrease in plasma IFN-γlevel and subsequently a gradual restoration as MWT and TWL recovered close to the physiological value.Intrathecal low-dose naloxone administration alone caused a 6 h slight rise in plasma IFN-γlevel,conversely high-dose intrathecal administration alone brought about a decrease for as long as 24 h compared to group C;Low-dose naloxone intrathecal administration significantly attenuated the suppression of plasma IFN-γlevel induced by postoperative pain,whereas high-dose naloxone administration enhanced the suppression of plasma IFN-γlevel induced by postoperative pain.Conclusion:Intrathecal administration of naloxone regulates IFN-γlevel via regulating pain threshold in rats with postoperative pain,and thus helps in immune protection,however hippocampal IFN-γlevel remains stable during the above interventions.