七氟醚对生理应激大鼠脊髓背角nNOS表达影响的研究

摘要

目的 观察七氟醚对生理应激大鼠旷场实验和脊髓背角nNOS表达的影响.方法 12只大鼠采用足底电击建立生理应激模型,造模前后分别进行旷场实验评估生理应激模型大鼠应激前后的行为学变化,采用完全随机设计将模型大鼠分为2组(n=6):分别行腹腔注射给药,生理盐水组注射生理盐水3 ml/kg,七氟醚组注射七氟醚3 ml/kg,待苏醒完全后,2组再行旷场试验.用免疫组织化学染色,测腰5节段水平大鼠脊髓背角nNOS表达.结果 旷场实验中,七氟醚组大鼠中央格数、外周格数、直立次数及修饰次数均减少(P＜0.01);脊髓背角免疫组化染色显示,nNOS阳性细胞集中Ⅰ、Ⅱ板层,七氟醚组较生理盐水组减少(P＜0.01).结论 生理应激大鼠脊髓背角的nNOS阳性细胞集中分布在Ⅰ、Ⅱ板层;七氟醚可以明显的抑制生理应激大鼠脊髓背角nNOS的表达,抑制大鼠应激状态.%Objective To investigate the effects of sevoflurane on the expression of neuronal nitric oxide synthase (nNOS) in the spinal dorsal horn of rats after physiological stress.Methods A physiological stress model was established where 12 rats were subjected to foot shock.The consequent behavioral changes were assessed using the open field test.The rats were randomly divided into two groups (n =6):a normal saline group (Group NS) where the rats were intraperitoneally injected with 3 ml/kg normal saline and a sevoflurane group (Group S) where the rats were intraperitoneally injected with 3 ml/kg of sevoflurane.After complete recovery,the open field test was used to assess the behavioral changes for both groups.The levels of nNOS in the spinal dorsal horn at L5 segment was measured by immunohistochemistry.Results In the open field test,the number of central squares,peripheral squares,standing and modification were decreased for Group S (P ＜ 0.01).According to immunohistochemistrical results,nNOS positive cells existed at Layers Ⅰ and Ⅱ.The amount of nNOS was lower in Group S group than that of Group NS (P ＜ 0.01).Conclusions The nNOS positive cells exist in Layers Ⅰ and Ⅱ of the spinal dorsal horn in rats after physiological stress.Sevoflurane can significantly inhabit the expression of nNOS in the spinal dorsal horn and physiological stress in rats.