纳豆激酶对动脉粥样硬化家兔凝血和纤溶功能的影响

Influence of nattokinase on coagulating and fibrinolytic function in atherosclerotic rabbit

目的:观察家兔口服纳豆激酶(NK)对血液凝血和纤溶功能的影响。方法:32只新西兰白兔随机分为4组,每组8只,包括空白对照组(A组)、模型组(B组)、低剂量NK组(C组)和高剂量NK组(D组),常规高脂饮食构建动脉粥样硬化模型。采用凝固法测定血浆凝血酶原(PT)、部分凝血活酶时间(APTT)和凝血因子Ⅰ(Fg)浓度;ELISA法测定血液纤溶酶原激活剂(tPA)和纤溶酶原激活剂抑制物(PAI-1)浓度、RT-PCR法检测主动脉组织tPA和PAI-1 mRNA的表达、免疫组化法检测主动脉组织PAI-1蛋白表达。结果:与A组相比,B组的PT明显缩短,C、D组的APTT明显延长,Fg含量明显下降(P<0.01),以D组更明显;D组的tPA浓度明显增加[(0.91±0.17)∶(1.25±0.23)μg/L,P<0.05],B组的PAI-1显著增加[(2.00±0.45)∶(2.75±0.84)μg/L,P<0.05];C、D组的tPA mRNA表达较B组明显增加(分别为1.22±0.23和1.33±0.16∶0.64±0.10,P<0.01),PAI-1 mRNA则显著减少(分别为1.34±0.17和1.31±0.09∶1.90±0.18,P<0.01);免疫组化染色显示A组、B组、C组和D组的单位面积动脉内膜及中膜PAI-1阳性染色标记物的平均A值分别为(155.86±28.19)、(190.49±19.80)、(148.52±9.86)和(138.80±3.13),P<0.05或P<0.01。结论:NK可明显提高血液纤溶活性、降低凝血活性,显著增加动脉硬化组织tPA mRNA的表达、减少PAI-1 mRNA和蛋白的表达。

Objective： To observe the influence of nattokinase （NK） on the blood and tissue fibrinolytic function in rabbits. Method：Thirty-two New Zealand white rabbits were divided into 4 groups, including controls group, models group, low dosage NK group and high dosage NK group. The prothrombin time, partial thromboplastin time and fibrinogen level were measured by coagulation method. The concentrations of tPA and PAI-1 were detected with ELISA method, and tPA mRNA and PAI-1 mRNA in aortic tissue were determined by RT-PCR method, and protein of PAI-1 was observed by immunohistochemistry method. Result：After 3 months oral administration of NK, the prothrombin time shortened significantly in models group, and partial thromboplastin time prolonged and fibrinogen level lowered in low, high and NK combined with LT group（P〈0. 01 and 0. 001）,and the level of tPA in high dose NK group increased obviously （0.91 ±0.17 ng/ml vs 1.25 ± 0.23μg/L, P〈0. 05）, and PAI-1 in models raised significantly （[2.00±0.45 ]μg/L vs [2.75±0.84]μg/L,P〈0.05）. Compared with models, the expression of tPA mRNA augmented （[1.22±0.23],[1.33±0. 16] vs [0. 64±0.10] respectively, P〈0. 001）, and PAI-1 mRNA lessened（1.34±0. 17,1.31±0.09 vs 1.90±0.18 respectively, P〈0. 001） in low, high dose NK group. The average optical （AO） of PAI-1 positive staining by immunohistochemistry were 155.86±28.19, 190. 49±19.80, 148. 52±9.86 and 138.80±3.13 （P〈0.05 and 0. 01） in controls, models, low and high dose NK group respectively. Conclusion：Oral administration of NK can increase the plasma fibrinolytic activity and decrease coagulating activity, augment the expression of tPA mRNA, and inhibit the expression of PAI-1 mRNA and protein in rabbit aortic atherosclerotic tissue.