甲基强的松龙对大鼠脊髓损伤后质膜钙ATP同工酶2和神经内分泌蛋白7B2表达的影响

Effect of high dose methylprednisolone on plasma membrane Ca^(2+)-ATPase isoform 2 mRNA and neuroendrocrine protein 7B2 mRNA expression after spinal cord injury

目的:探讨甲基强的松龙(MP)对大鼠脊髓损伤后质膜钙ATP同工酶2(plasm amembrane Ca2+-AT-Paseiso form2)和神经内分泌蛋白7B2(neuroendrocrine protein 7B2)表达的影响。方法:SD大鼠30只。随机分为假手术组、单纯脊髓损伤组(损伤组)、脊髓损伤+大剂量甲基强的松龙治疗组(MP组)。应用改良Allen打击法致T8脊髓损伤。MP组大鼠尾静脉内注射大剂量MP(30mg/kg)。损伤后24h将损伤平面上下0.5cm的脊髓组织切取,进行RT-PCR反应,检测质膜钙ATP同工酶2和神经内分泌蛋白7B2的基因表达情况。结果:在术后24h假手术组质膜钙ATP同工酶2mRNA表达的相对丰度为0.3232±0.0032,损伤组为0.1518±0.069,MP组为0.5721±0.1325,三组间有显著性差异,MP组大于假手术组(P<0.05),假手术组大于损伤组(P<0.01)。假手术组神经内分泌蛋白7B2mRNA表达的相对丰度为1.2289±0.1189,损伤组为0.5843±0.2951,MP组为1.2890±0.2268,MP组和假手术组与损伤组比较差异有显著性(P<0.01),MP组与假手术组比较差异无显著性(P>0.05)。结论:脊髓损伤后,细胞合成质膜钙ATP同工酶2明显降低,邻近损伤处的脊髓组织神经内分泌蛋白7B2的表达降低,大剂量MP能显著促进并逆转质膜钙ATP同工酶2表达的丰度,促进神经内分泌蛋白7B2的表达,发挥细胞保护作用。

Objective：To investigate effect of high dose methylprednisolone（MP） on plasma membrane Ca^2＋- ATPase isoform 2 mRNA and neuroendrocrine protein 7B2 mRNA expression after spinal cord injury.Method： Thirty SD rats were divided equally into sham group,Allen＇s weight drop injury group and injury followed by high dose MP group.Twenty four hours after the surgery,the spinal lesion and neighboring areas were removed for test of plasma membrane Ca^2＋-ATPase isoform 2 mRNA and neuroendrocrine protein 7B2 mRNA expression by Retrograde Polymerase Chain Reaction technique （RT-PCR）.Result：The plasma membrane Ca^2＋-ATPase isoform 2 mRNA expression were 0.3232±0.0032,0.1518±0.069 （P〈0.01）,0.5721±0.1325 （P〈0.01） in three group respectively which decreased significantly after spinal cord injury and increased after treatment with MP.The neuroendrocrine protein 7B2 mRNA expression were 1.2289±0.1189,0.5843±0.2951 （P〈0.05）, 1.2890±0.2268（P〈0.01） in three group respectively which decreased significantly after spinal cord injury and increased after treatment with MP.Conclusion：MP can greatly increase the expression of plasma membrane Ca^2＋-ATPase isoform 2 and epidermal neuroendrocrine protein 7B2 after spinal cord injury.