苦荞黄酮对脑缺血再灌注大鼠神经功能及脑组织一氧化氮合酶表达的影响

Effect of Tartary Buckwheat Flavonoids on Neurological Function and Expression of Cerebral Nitric Oxide Synthases in Rats with Focal Cerebral Ischemia-Reperfusion

目的探讨苦荞黄酮对大鼠局灶性脑缺血再灌注损伤的保护作用。方法雄性SD大鼠50只随机分为正常组、模型组、100、75和50 mg·kg-1剂量治疗组各10只。模型组和治疗组采用线栓法制备大鼠右侧大脑中动脉栓塞缺血再灌注模型。治疗组术后连续7 d以100、75和50 mg·kg-1浓度苦荞黄酮灌胃,每日3次。治疗7 d后进行各组大鼠神经行为学测试,应用免疫组织化学SP法检测大鼠脑组织诱导型一氧化氮合酶、内皮型一氧化氮合酶的表达。结果与模型组比较,治疗组神经功能评分增高(P<0.05),治疗组诱导型一氧化氮合酶表达显著降低(P<0.01,P<0.05),内皮型一氧化氮合酶表达显著增高(P<0.01)。结论苦荞黄酮可改善脑缺血再灌注损伤大鼠的神经功能,能降低脑缺血再灌注大鼠脑组织诱导型一氧化氮合酶表达、增强内皮型一氧化氮合酶表达,对神经元具有保护作用。

OBJECTIVE To investigate the protective effect of the decoction of tartary buckwheat flavonoids on focal cerebral is- chemia-reperfusion injury of rats. MEHTODS Fifty male SD rats will be randomly divided into normal group, cerebral ischemia- reperfusion group （model group） , high dose of tartary buckwheat flavonoids group, middle dose of tartary buckwheat flavonoids group and low dose of tartary buckwheat flavonoids group, each groups of 10 rats. A rat model of the right middle cerebral artery occlusion/reper- fusion （MCAO） was established by the filament method. After being operated, treatment-group rats will be administered 100,75 and 50 mg · kg -1of the decoction of tartary buckwheat flavonoids three times a day for 7 consecutive days. after administrated for 7 d, rats in each group will undergo neurobehavioral tests. Expressions of cerebral inducible nitric oxide synthase（iNOS） and endothelial nitric ox- ide synthase（eNOS） were measured by SP immunohistochemistry. The optical density value（OD） was measured by imaging analysis, and the percentage of cells with iNOS and eNOS positive expression was analyzed under light microscope. RESULTS Compared with ischemia-reperfusion group, neurological function score increased in the decoction of tartary buckwheat flavonoids groups. Treatment groups had lower expression level of iNOS but higher expression level of eNOS than those in the model groups（P 〈 0. 01, P 〈 0. 05 ）. The number of neurons of Hippocampal CA1 was increased （ P 〈 0. 05 ）. CONCLUSION Tartary buckwheat flavonoids can improve neurological function and decrease the expression of iNOS and increase the expression of eNOS in cerebral ischemia-reperfusion rats, which may contribute to the protection of neural function.