小剂量纳洛酮对小鼠皮下注射瑞芬太尼引起痛觉过敏的影响

Effects of low - dose naloxone on remifentail - induced hyperalgesia in rats

目的观察小剂量纳洛酮对小鼠皮下一次性注射瑞芬太尼引起痛觉过敏的影响。方法50只雌性昆明种小鼠随机均分为5组：纳洛酮组（NS组）、瑞芬太尼组（RS组）、瑞芬太尼与各剂量纳洛酮（100ng·kg^-1、10ng·kg^-1、1ng·kg^-1）合用组（RN1、RN2、RN3组），瑞芬太尼的剂量均为80μg·kg^-1，每组10只。腹腔注射纳洛酮或生理盐水15min后皮下注射瑞芬太尼，观察比较基础痛阈与给瑞芬太尼后5、20、35、60、90、120、150、180min对小鼠热板法痛阈（HPPT）的影响。结果与基础痛阈比较，NS组在5～180min内HPPT均未见明显改变（P〉0．05）；RS组5—35min内HPPT延长，60rain时HPPT与基础痛阂比较无统计学差异（P〉0．05），而90～120min内HPPT缩短（P〈0．05或P〈0．01）；RN1、RN2、RN3组在5—60min内HPPT延长（P〈0．01）；与RS组比较，RN1、RN2、RN3组在5～35min内HPPT无统计学差异（P〉0．05），但在60～120min内HPPT均显著增加（P〈0．01）。结论1—100ng·kg^-1的纳洛酮能缓解甚至避免瑞芬太尼引发的痛觉过敏现象。

Objective To observe the effects of low - dose naloxone on hyperalgesia in rats induced by a single sub- cutaneous injection of remifentail. Methods Fifty female rats were randomly divided into five groups （ n = 10） , accord- ing to their treatment with naloxone （group NS）, remifcntail （group RS） , 80 μg/kg remifentail ＋ 100 ng/kg naloxone （ group RN1 ） , 80 μg/kg remifentail ＋ 10 ng/kg naloxone （ group RN2 ） and 80 μg/kg remifentail ＋ 1 ng/kg naloxone （ group RN3 ）. Remifentanil was subcutaneously injected 15 min after intraperitoneal administration of naloxone or normal saline. Then, pain threshold in hot - plate test （HPPT） and basal HPPT were compared 5, 20, 35, 60, 90, 120, 150, and 180 min after remifentanil treatment. Results Compared with basal line, no obvious changes were seen as to the HPPT of group NS from 5 to 180 min （P 〉0.05）. Meanwhile, compared with basal line, group RS produced a higher HPPT from 5 to 35 min, which showed no statistical difference at 60 rain （ P 〉 0.05 ） , but then became lower from 90 to 120 min （P 〈 0. 05, P 〈 0.01 ）. The HPPT of groups RN1, RN2 , and RN3 was extended from 5 to 60 min （ P 〈 0.01 ） and showed no obvious changes from 90 to 120 min （P 〉0.05）. When compared with group RS, groups RN1, RN2 and RN3 caused no obvious differences in HPPT from 5 to 35 rain （ P 〉 0.05 ） , which however was significantly longer from 90 to 120min （P 〈0.01 ）. Conclusion Naloxone can alleviate or even prevent remifentanil -induced hypcralgesia at doses of 1 to 100 ng/kg.