Received 2001-12-04 Accepted 2002-01-25

This project was supported by the National Natural Science Foundation of China (No. 39970925), the Research Fund for Doctoral Program of Higher Education (No. 9835).

*Corresponding author. Tel: +86-21-64041900-2397; Fax: +86-21-64174579; E-mail gcwu@shmu.edu.cn

Acta Physiologica Sinica Aug. 2002, 54 (4), 325~328

Research Paper

Thermal hyperalgesic effects induced by intracerebroventricular injection of interleukin-1β in rats

JI Guang-Chen1, 2, MA Fei1, ZHANG Yu-Qiu1, WU Gen-Cheng1, *

1Department of Neurobiology, State Key Laboratory of Medical Neurobiology, Medical Center of Fudan University (The Former Shanghai Medical University), Shanghai 200032; 2Department of Acupuncture, Shandong University of Traditional Chinese Medicine, Jinan 250014

Abstract: The present study was to investigate the effects of intracerebroventricular (i.c.v.) injection of interleukin-1β (IL-1) on thermal nociception in SD rats. The rats were divided into control and drug-administration groups. The animals of control group were given vehicle solution via i.c.v. injection. The animals of drug-administered groups were given IL-1 at different doses (5, 50 and 500 pg/kg b.w.) via i.c.v. injection. IL-1 receptor antagonist (IL-1ra, 50 ng/kg) was injected 20 min before injection of IL-1 or vehicle solution. The nociceptive threshold, which was represented as paw withdrawal latency (PWL), to a noxious thermal stimulation was measured using an analgesiameter. I.c.v. injection of IL-1 dose-dependently shortened the PWL. At the dose of 500 pg/kg, the shortening of the PWL occurred at 20 min, reaching a peak within 40 min, lasted 100 min after injection, then gradually returned to the baseline level. Pretreatment with IL-1ra completely blocked the effects of IL-1-induced shortening in PWL. The results obtained suggest that IL-1 may induce hyperalgesia in rats through binding to IL-1 receptors in the brain.

Key words: interleukin-1; thermal hyperalgesia; brain

脑室注射白介素-1 引起的热痛敏作用

姬广臣1,2, 马 飞1, 张玉秋1, 吴根诚1,*

1复旦大学上海医学院神经生物学教研室, 医学神经生物学国家重点实验室, 上海 200032; 2山东中医药大学针灸基础研究室,

济南 250014

摘 要: 实验在SD大鼠上应用脑室微量注射和辐射热测痛的方法, 研究了脑内微量注射白介素-1 对大鼠痛阈的影响。实验大鼠分为给药组和对照组, 在给药组大鼠脑室注射不同剂量的白介素-1 (5、 50和500 pg/kg), 对照组大鼠脑室注射配药液。白介素-1受体拮抗剂 (IL-1ra, 50 ng/kg)在脑室注射白介素-1 前20 min给予。实验以大鼠对光热刺激引起的缩爪反射潜伏期为痛阈指标。结果表明, 脑室注射白介素-1 可显著缩短大鼠对光热刺激的缩爪反射潜伏期, 并具有剂量依赖性关系。脑室给予500 pg/kg的白介素-1 20 min后, 大鼠对光热刺激的缩爪反射潜伏期显著缩短, 40 min时达峰值, 然后逐渐恢复。该作用可被白介素-1 受体拮抗剂阻断。结果提示脑中白介素-1 可通过作用于白介素-1受体引起热痛敏作用。

关键词: 白介素-1 ; 热痛敏作用; 脑

学科分类号: Q426