Jinks Steven L, Antognini Joseph F, Martin John T, Jung S- W, Carstens Earl, Atherley Richard
Department of Anesthesiology and Pain Medicine, University of California, Davis 95616, USA.
Anesth Analg. 2002 Dec;95(6):1622-8, table of contents. doi: 10.1097/00000539-200212000-00028.
We investigated the effects of isoflurane and halothane on the induction of fos-like immunoreactivity (FLI) in the rat lumbosacral spinal cord after supramaximal noxious mechanical stimulation of the hindpaw. Compared with unstimulated controls (0.9% isoflurane), noxious stimulation at 0.9%-1.5% elicited significant (0.9%-1.5% isoflurane) increases in FLI bilaterally. FLI was distributed mainly in the superficial dorsal horn (laminae I-III) and, to a lesser extent, in the deep dorsal horn (laminae IV-VI) and intermediate zone (lamina VII), with three- to fivefold greater labeling ipsilaterally. At 1.8% isoflurane, mean FLI counts in all laminar regions were significantly smaller (1.7 +/- 1.3 per section) compared with the other concentrations (11.4 +/- 9.5, 7.5 +/- 6.8, and 9.7 +/- 6.6 at 0.9%, 1.2%, and 1.5%, respectively) but were not different from unstimulated controls. At sacral levels, we observed a bilateral distribution of FLI primarily in superficial laminae in unstimulated controls that was not significantly different at any isoflurane concentration. FLI counts were not significantly different across groups receiving halothane (0.9%-1.5%). FLI was reduced only at isoflurane concentrations that depressed both gross, purposeful movement and reflex withdrawal, whereas halothane did not cause depression even at concentrations that depressed withdrawal reflexes. Isoflurane and halothane may have differing effects on neuronal function and responses to noxious stimulation.
Isoflurane depressed neuronal activity in the spinal cord as measured with fos-like immunoreactivity (FLI), but this occurred only when reflex withdrawal responses were abolished. Halothane, however, did not depress FLI, even at concentrations sufficient to block reflex withdrawal. These two anesthetics may have differing effects on neuronal function and responses.
我们研究了异氟烷和氟烷对大鼠后爪超最大伤害性机械刺激后腰骶脊髓中类Fos免疫反应性（FLI）诱导的影响。与未刺激的对照组（0.9%异氟烷）相比，0.9%-1.5%的伤害性刺激双侧均引起FLI显著增加（0.9%-1.5%异氟烷）。FLI主要分布在背角浅层（I-III层），在背角深层（IV-VI层）和中间带（VII层）分布较少，同侧标记比对侧多三到五倍。在1.8%异氟烷时，与其他浓度相比（0.9%、1.2%和1.5%时分别为11.4±9.5、7.5±6.8和9.7±6.6），所有层状区域的平均FLI计数显著更小（每切片1.7±1.3），但与未刺激的对照组无差异。在骶段水平，我们观察到在未刺激的对照组中FLI主要双侧分布于浅层，在任何异氟烷浓度下均无显著差异。接受氟烷（0.9%-1.5%）的各组之间FLI计数无显著差异。仅在异氟烷浓度降低总体、有目的运动和反射性退缩时FLI才降低，而氟烷即使在降低退缩反射的浓度下也不会引起抑制。异氟烷和氟烷对神经元功能和对伤害性刺激的反应可能有不同影响。
用类Fos免疫反应性（FLI）测量，异氟烷可降低脊髓中的神经元活动，但仅在反射性退缩反应被消除时才会发生。然而，氟烷即使在足以阻断反射性退缩的浓度下也不会降低FLI。这两种麻醉剂对神经元功能和反应可能有不同影响。
