重组水蛭素Ⅲ乳糜微粒抗凝血抗血栓作用的研究及其口服吸收机制初探(英文)

Effect of Recombinant Hirudin Variant III Emulsive Microparticles on Thrombosis and the Study on Its Oral Absorption Mechanism

目的:对重组水蛭素rHⅧ乳糜微粒(rHⅧ EP)的抗血栓及抗凝效果进行了药效学评价并对其口服给药的吸收机制进行了初步探索。方法:分别采用正常大鼠, 弥散性血管内凝血(DIC)模型大鼠及下腔静脉凝血(IVC)模型大鼠测定rHⅧ乳糜微粒的药效; 将rHⅧ以异硫氰酸荧光黄(FITC)标记后通过Caco-2 单细胞模型和肠外翻模型测定乳糜微粒的初步吸收动力学。结果:体内实验中, rHⅧ EP可延长凝血酶时间(TT), 凝血时间(CT), 并抑制血栓的形成。转运实验证明, rHⅧ在肠的各个部位均有吸收, AP面向BL面的转运速率Papp为(2.68 ± 0.14) ×10-6 cm·s-1, BL到AP的Papp值为(3.02 ± 0.66) ×10-6 cm·s-1, 提示其在肠内的运输方式主要为被动运输。相较于静脉注射方式, rHⅧ乳糜微粒的口服绝对生物利用度为 11.42%。结论:rHⅧ EP具有抗血栓和抗凝作用以及适合的生物利用度。在此基础上, 作者首次提出将rHⅧ制成口服给药的乳糜微粒形式存在良好的开发潜力。

Aims： To evaluate the antithrombosis of recombinant hirudin variant Ⅲ emulsive microparticles （rHⅧ EP） and disclose its mechanism via oral administration. Methods： Normal and DIC （disseminated intravascular coagulation） rats as well as IVC （inferior caval vein） thrombosis rats were used to determinate the pharmacodynamics of rHVIII. rHⅧ was labeled with FITC （fluorescein isothiocyanate） to test the absorption of emulsive microparticles using Caco-2 monolayer model and everted gut sacs model. Results： rHⅧ EP was able to prolong thrombin time, clotting time and inhibit thrombus formation in vivo. rHⅧ EP could be absorbed in the whole intestinal sections. Transport experiment indicated that the Papp value was （2.68 ± 0.14） ×10-6 cm·s-1 from AP side to BL side, and （3.02 ± 0.66） ×10-6 cm·s-1 from BL side to AP side, respectively, indicating that rHⅧ is absorbed in the intestine through passive transport. Compared with intravenous route, the absolute bioavailability of rHⅧ EP via oral route was 11.42%. Conclusions： rHⅧ EP has anti-thrombosis and anticoagulation effects with proper bioavailability. Our study here elucidated for the first time that rHⅧ EP delivered via oral route has potentiality in development.