John J M, Kaneko M, Hammond D L
Department of Anesthesia and Critical Care, University of Chicago, Chicago, IL 60637, USA.
Brain Res. 1998 Jun 1;794(2):320-4. doi: 10.1016/s0006-8993(98)00269-8.
Intrathecal (i.t.) administration of the gamma-aminobutyric acid (GABA)A receptor antagonist bicuculline enhances pain behaviors in the formalin test. This study examined whether bicuculline also increases the peripheral inflammation induced by formalin. Subcutaneous injection of 0.25 to 5.0% formalin in the plantar surface of one hindpaw of the rat produced a concentration-dependent increase in plasma extravasation as measured by the Evans Blue method. Pretreatment with 0.3 microg i.t. bicuculline neither enhanced nor suppressed formalin-induced plasma extravasation. This dose of bicuculline also did not affect plasma extravasation induced by injection of 3% kaolin/3% carrageenan in the knee of the rat. These data indicate that the enhancement of formalin-induced pain behaviors by i.t. bicuculline is not secondary to enhanced peripheral inflammation, but more likely reflects enhancement of nociceptive transmission in the spinal cord.
鞘内注射γ-氨基丁酸（GABA）A受体拮抗剂荷包牡丹碱可增强福尔马林试验中的疼痛行为。本研究检测了荷包牡丹碱是否也会增加福尔马林诱导的外周炎症。通过伊文思蓝法测定，在大鼠一侧后爪足底皮下注射0.25%至5.0%的福尔马林会使血浆外渗呈浓度依赖性增加。鞘内注射0.3微克荷包牡丹碱预处理既不增强也不抑制福尔马林诱导的血浆外渗。该剂量的荷包牡丹碱也不影响在大鼠膝关节注射3%高岭土/3%角叉菜胶诱导的血浆外渗。这些数据表明，鞘内注射荷包牡丹碱增强福尔马林诱导的疼痛行为并非继发于外周炎症增强，而更可能反映脊髓伤害性感受传递的增强。
