孤啡肽受体拮抗剂对机械性损伤神经元存活率的影响

摘要

Objective Earlier study showed that orphanin FQ was increased significantly after traumatic brain injury. This study aims to investigate whether blocking of the orphanin receptor (ORL-1) affects neuronal viability after traumatic neuronal injury. Methods Mechanic injury neuronal model was established. The neuroprotective effects of [ Nphel ]-NC( 1-13)-NH2 (Nphe), an antagonist of ORL-1, on injured neurons were observed by methyl thiazolyl tetrazolium (MTT) assay, detection of activity of the lactate dehydrogenase (LDH) and calcium level. Results Nphe increased the neuronal viability in a dose-dependent manner after traumatic neuronal injury in vitro measured by MTT assay. Different dose of Nphe (30 nM, 300 nM, 1 200 nM) increased the neuronal viability (56% ± 5% , 67% ± 7% , 72% ± 8%) compared with injury group (46% ± 4% , P<0.05). And Nphe produced a decrease in intra-cellular calcium level at 12 h (P <0. 05) and LDH concentrations at 12 h, 48 h (P <0.05). Conclusion As an antagonist of the OFQ receptor, Nphe can improve neuronal viability in cultured neurons from rat embryonic cortex after traumatic neuronal injury.%目的 既往研究表明,孤啡肽在脑损伤后的表达明显升高,本研究通过特异性阻断孤啡肽受体( opioid-receptor-like receptor,ORL-1),观察对受损神经元是否具有保护作用.方法 建立神经元机械性损伤模型,用孤啡肽受体特异性阻断剂([ Nphe1 ]-NC( 1-13)-NH2,Nphe)阻断孤啡肽受体,通过四甲基偶氮唑蓝(methyl thiazolyl tetrazolium,MTT)法、乳酸脱氢酶(lactate dehydrogenase,LDH)活性,钙离子水平测定,研究Nphe对机械性损伤神经元存活率的影响.结果 MTT法测定神经元机械性损伤后12 h细胞存活率显示:单纯损伤组细胞存活率为46%±4%,与对照组相比显著下降(P＜0.05),不同剂量Nphe(30、300、1 200 nM)干预组的细胞存活率分别为56%±5%、67%±7%、72%±8%,与单纯损伤组存活率46%±4%相比差异显著(P＜0.05).LDH活性检测提示损伤后12 h和48 h,Nphe干预组LDH活性与损伤组相比有显著差异(P＜0.05).神经元机械性损伤后12 h,Nphe能够降低损伤后细胞内钙离子水平(P＜0.05).结论 ORL-1的特异性拮抗剂Nphe能够减少机械性损伤后继发性神经元损害,对神经元具有一定的保护作用.