补阳还五汤对血管性痴呆大鼠海马NR2B蛋白及其mRNA表达的影响

目的 观察补阳还五汤对血管性痴呆(vascular dementia,VD)大鼠海马N-甲基-D-门冬氨酸受体亚单位2B(N-Methyl-D-asparate receptor subunit 2B,NR2B)蛋白及其mRNA表达的影响,探讨补阳还五汤治疗VD的机制.方法 四血管阻断(four vessel occlusion,4VO)法制备VD大鼠模型.设立假手术组、VD模型组、尼莫地平组(20mg·kg-1·d-1,灌胃30d)和补阳还五汤治疗组(50g生药·kg-1·d-1,灌胃30d).Morris水迷宫检测大鼠学习记忆能力的改变,免疫组化和Western-Blot技术检测大鼠海马神经元NR2B蛋白的变化,实时荧光定量PCR技术检测大鼠海马NR2B mRNA表达的变化.结果 与假手术组大鼠逃避潜伏期(24.18±7.90)s]和平均探索次数(7.99±1.32)次/min]相比,VD模型组大鼠逃避潜伏期(51.25±18.28)s]延长和平均探索次数(5.26±0.74)次/min]减少(P<0.05);补阳还五汤组(25.91±9.56)s和(7.52±1.27)次/min]明显改善了模型大鼠学习、记忆成绩(P<0.05);假手术组、尼莫地平组与补阳还五汤治疗组之间差异无显著性(P>0.05).VD模型组大鼠的NR2B蛋白(0.33±0.06)及其mRNA(593±53)表达水平较假手术组(0.71 ±0.13)、(5887±501)明显降低(P<0.05);补阳还五汤治疗组大鼠海马的NR2B蛋白(0.66±0.11)及其mRNA(5692±482)表达水平较模型组的表达明显升高(P<0.05);假手术组、尼莫地平组组与补阳还五汤治疗组之间差异无显著性(P>0.05).结论 补阳还五汤可以改善VD大鼠学习记忆能力,其机制可能与减轻脑缺血再灌注对海马CAI区神经元的损伤及促进海马组织NR2B蛋白及其mRNA的表达有关.

The effect of buyanghuanwu decoctinn on expression of immunoreactive protein and mRNA of NMDA receptor 2B subunit in rats hippocampal with vascular dementia

Objective To observe the effect of buyanghuanwu decoction on expression of immunoreactive protein and mRNA of NMDA receptor 2B subunit in rats hippocampal with vascular dementia to investigate the mechanism of buyanghuanwu decoction. Methods One hundred and forty-four rats were randomly divided into 4 groups: sham-operated group, VD model group,nimodipine group and buyanghuanwu decoction treatment group. The rats models of vascular dementia were built up by four vessels occlusion method. VD rats were treated with in-tragastrical buyanghuanwu decoction suspension (50 pharmacognostic g·kg-1·d-1) and nimodipine suspension (20 mg·kg-1·d-1) for 30 days. The learning and memory abilities were evaluated by Morris water maze tests. The change of NR2B protein in hippocampal of each group of rats were measured with immunohistochemistry and Western blot techniques and the expression of NR2B mRNA in hippocampus were observed by real-time fluorescence quantitative PCR techniques. Results Water maze tests,compared with sham-operated group((24. 18 ± 7.90)s,(7.99 ±1.32)/min) ,the escape latency(51. 25 ±18.28)s to explore the extension and the average spatial probe number ((5. 26 ±0. 74)/min) reduced in VD model group (P < 0. 05). Buyanghuanwu decoction ((25.91 ±9.56)s,(7. 52 ± 1. 27)/min) had significantly improved the above-mentioned rat model of learning and memory performance (P<0.05). There was no significant difference among sham-operated group,nimodipine group and buyanghuanwu decoction treatment group (P>0. 05). Similarly,as compared rats with sham-operated group(0.71 ±0.13), (5887 ±501), the expression of NR2B protein (0. 33 ± 0. 06) and its mRNA(593 ±53) were apparently decreased in VD rats (P< 0.05). The expression of NR2B protein(0.66 ±0. 11) and its mRNA (5692 ±482) in neuron of hippocampus were increased by buyanghuanwu decoction compared with the model group (P < 0. 05), and no difference was discovered between sham operation group and nimodipine group (P > 0.05).Conclusions Buyanghuanwu decoction improves the learning and memory abilities in VD rats, the therapeutic mechanism was concerned with lessening the injury of neurons on CA1 field in hippocampus and promoted the expression of NR2B protein and its mRNA.