复方倍他米松局部注射后自体髓核移植模型大鼠脊髓及背根神经节中P物质和降钙素基因相关肽变化

Changes in substance P and calcitonin gene-related peptide in the spinal cord and dorsal root ganglia in a rat model of autologous transplantation of nucleus pulposus after local injection of compound betamethasone

背景:复方倍他米松注射液治疗椎间盘突出症临床应用广泛,但其具体作用机制尚不明确。目的:探讨局部注射复方倍他米松对自体髓核移植模型大鼠脊髓及背根神经节中P物质和降钙素基因相关肽的影响。方法:36只SD大鼠随机分为4组,即:空白组、模型组、假手术组、西药组,每组9只。模型组和西药组适应性喂养1周后手术制作大鼠自体髓核移植模型。于术后第3,7,12天,模型组和假手术组给予128.25μL生理盐水,西药组给予复方倍他米松注射液13.5μL+2%利多卡因注射液67.5μL。末次给药12 h取L4-6节段脊髓及背根神经节,采用免疫荧光染色方法测定两种组织中P物质和降钙素基因相关肽的含量。结果与结论:各组大鼠脊髓、背根神经节中P物质和降钙素基因相关肽平均荧光强度比较,差异有显著性意义(P<0.01),进一步两两比较:与空白组、假手术组相比较,模型组大鼠脊髓、背根神经节中P物质和降钙素基因相关肽含量显著性增高(P<0.01),证明模型复制可靠;与模型组、假手术组相比较,西药组大鼠脊髓、背根神经节中P物质和降钙素基因相关肽含量显著性降低(P<0.01)。结果表明复方倍他米松治疗腰椎间盘突出症的作用机制,可能是通过抑制背根神经节神经元合成和分泌P物质,清除背根神经节中P物质和降钙素基因相关肽,减少其向脊髓传递,从而抑制和缓解疼痛。

BACKGROUND： Compound betamethasone injection has been widely used to treat intervertebral disc herniation, but its precise mechanism remains unclear. OBJECTIVE： To explore effects of local injection of compound betamethasone on substance P and calcitonin gene-related peptide in spinal cord and dorsal root ganglia of rat models undergoing autologous transplantation of nucleus pulposus. METHODS： A total of 36 Sprague-Dawley rats were randomly assigned to four groups： blank group, model group, sham surgery group, and western medicine group, with 9 rats in each group. After 1 week of adaptive feeding, rat models of autologous transplantation of nucleus pulposus were established in the model and western medicine groups. At 3, 7 and 12 days after surgery, the rats were given 128.25 μL saline in the model and sham surgery groups. The rats in the western medicine group were administered Betamethason Compound Injection 13.5 μL ＋ 2% Lidocaine Injection 67.5 μL. At 12 hours after final administration, L4-6 segments of the spinal cord and dorsal root ganglion were obtained, and substance P and calcitonin gene-related peptide contents in L4-6 segments of the spinal cord and dorsal root ganglion were determined using immunofluorescence staining. 〈br〉 RESULTS AND CONCLUSION： Significant differences in mean fluorescence intensity of substance P and calcitonin gene-related peptide were detected in rat spinal cord and dorsal root ganglion in each group （P 〈 0.01）. Further paired comparison showed that compared with the blank and sham surgery groups, substance P and calcitonin gene-related peptide contents were significantly higher in the spinal cord and dorsal root ganglion in the model group （P 〈 0.01）, which verified that models could be replicated and were reliable. Compared with the model and sham surgery groups, substance P and calcitonin gene-related peptide contents were significantly lower in the spinal cord and dorsal root ganglion of rats in the western medicine group （P 〈 0.01）. Above results confirmed that Compound Betamethasone Injection for treating lumbar intervertebral disc herniation eliminated substance P and calcitonin gene-related peptide in dorsal root ganglion possibly by inhibiting dorsal root ganglion neuron synthesis and secreting substance P and reduced their transmission to the spinal cord, resulting in inhibiting and lessening pain.