异氟醚减少甲醛刺激诱导大鼠脊髓Fos蛋白的表达

Isoflurane reduces Fos-like protein expression in rat spinal cord in response to peripheral noxious stimulation

目的 观察异氟醚对甲醛痛刺激诱发大鼠脊髓Fos蛋白的影响 ,探讨异氟醚在脊髓的可能作用部位。方法 S -D大鼠 3 5只随机分为 5组 ,分别于大鼠左足底皮下注射生理盐水 0 .1ml(NS组 )、0 .17mol L甲醛 0 .1ml(F组 )、0 .17mol L甲醛 0 .1ml皮下注射后立即吸入 1.15 % (体积比 )异氟醚 (FI1 .0 组 )、0 .17mol L甲醛 0 .1ml皮下注射后立即吸入 1.5 % (体积比 )异氟醚 (FI1 .3组 ) ,另单纯吸入 1.5 % (体积比 )异氟醚 (I1 .3组 )。模型制作后观察有无痛行为学表现 (舔、咬、抓左后肢 )。 1.5h后 ,取相应脊髓节段 (L4～ 6 )标本免疫组织化学法显示Fos蛋白阳性细胞。结果 ①异氟醚可抑制大鼠甲醛诱发的痛行为表现 ;②异氟醚可抑制甲醛刺激引起的脊髓深层的c -fos表达。结论 脊髓深层可能是异氟醚抗外周伤害性刺激作用的关键部位。

Objective To investigate the effect of isoflurane on formaldehyde-induced c-fos expression in the spinal cord.?Methods The noxious stimulus was a subcutaneous injection of formaldehyde (0.17 mol/L 0.1ml) applied to the center of the left hind paw. Thirty-five SD rats were randomly divided into 5 groups: normal saline group (NS), formaldehyde group (F), 1.5% isoflurane group (I 1.3 ), formaldehyde with 1.15% isoflurane group (FI 1.0 ) and formaldehyde with 1.5% isoflurane group (FI 1.3 ). The pain behaviors in the rats were noted. One half an hour later, the rats were sacrificed and perfused to make sections of the spinal cord. The sections were were immunostained with anti c-fos antibody to count the number of Fos-like immunoreactive (Fos-LI) neurons in various laminae.?Results ①Following the injection of formaldehyde into the left hind paw, the rats showed distinctive pain behaviors, such as licking, gnawing and raising of the ipsilateral paw. The pain behaviors were depressed by isoflurane inhalation. ② Formaldehyde-induced Fos-LI was mainly distributed in laminaeⅠ～Ⅱ and laminae Ⅴ～Ⅵ of ipsilateral spinal dorsal horn. Isoflurane inhibited Fos-LI expression in the deeper layers, not in the superficial layers (laminae Ⅰ and Ⅱ).?Conclusion The deeper layers of the spinal cord in the rat may be the key site of isoflurane's antinoxious action.