GABAA receptor partially mediated propofol-induced hyperalgesia at superspinal level and analgesia at spinal cord level in rats

作     者：Qin-yun WANG2,3, Jun-li CAO2, Yin-ming ZENG2, Ti-jun DAI2,4 2Jiangsu Institute of Anesthesiology, Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou, 221002, China 3Department of Anesthesiology, the1st Affiliated Hospitalof Soochow University, Suzhou 215006, China 

作者机构：Jiangsu Institute of Anesthesiology Jiangsu Province Key Laboratory of Anesthesiology Department of Anesthesiology the 1st Affiliated Hospital of Soochow University 

出 版 物：《Acta Pharmacologica Sinica》 (中国药理学报(英文版))

年 卷 期：2004年第25卷第12期

页      面：53-59页

核心收录：

学科分类：1002[医学-临床医学] 100204[医学-神经病学] 10[医学] 

基　　金：Project supported by the National Natural Science Foundation of China No 39970715 and the NationalNatural Science Foundation of Jiangsu Province No BK2001143 

主　　题：GABA receptors propofol pain ventrolateral periaqueductal gray spinal cord 

摘      要：AIM: To observe effects of propofol on nociceptive response at superspinal and spinal level in rats. METHODS: Two hundreds and fifty-eight Sprague-Dawley male rats were randomized into thirty-two groups. Propofol and bicuculline were microinjected into lateral ventricle (icv), ventrolateral periaqueductal gray (vlPAG), intrathecal (ith), and intraperitoneal (ip). The noxious responses were evaluated by hot plate and formalin test. RESULTS: In hot-plate test, systemic and superspinal administration of propofol (40 mg·kg-1 ip, 100 μg in 10 μL, icv, and 4 μg in 0.4 μL vlPAG microinjection) produced hyperalgesia (P0.01). Hyperalgesia induced by vlPAG microinjection of propofol was significantly antagonized by 69.8 %, 71.2 %, 98.8 % at 10, 20, and 30 min by microinjection of bicuculline (10 ng in 0.4 μL, vlPAG) (P0.01). Analgesia induced by ith propofol (100 μg·10 μL-1) was antagonized about 81.3 %, 54.8 %, 80.8 %, and 97.4 % at 10, 20, 30 and 40 min by ith bicuculline (P0.05). In formalin test, systemic and superspinal administration of propofol (40 mg·kg-1 ip, 4 μg in 0.4 μL, vlPAG) also produced hyperal- gesia (P0.01). The increased formalin pain scores were antagonized about 57.1 % by bicuculline (10 ng, vlPAG) (P0.05) at 60 min after formalin injection. The decreased formalin pain scores induced by ith propofol (100 μg in 10 μL) were antagonized about 66.7 % at 30 min by ith bicuculline (P0.05) after formalin injection. Hyperalgesia produced by ip propofol in both hot plate and formalin test could not be antagonized by vlPAG administration of bicuculline. CONCLUSION: GABAA receptor partly mediated propofol-induced hyperalgesia at superspinal and analgesia at spinal cord in rats.