血液对新型人工心瓣膜作用的基础理论研究

Research on the rationale of the reaction of blood on the artificial heart valve

目的探索血液对人工心瓣膜作用的基础理论。方法①比较新型心瓣膜材料氧化钛(Ti-o)与现今临床试用的热解碳(LITC)理化特性;②体外血小板(PL)粘附试验;③放射性I125检测Ti-o与LITC表面纤维蛋白原(FIG)的吸附量;④乳酸脱氢酶(LDH)检测PL的吸附量;⑤动物犬股动脉内埋置,6个月后扫描电镜(SEM)比较吸附PL的形态和吸附量。结果 Ti-o属N型半导体,界面能近似FIG。体内、外对FIG与PL的吸附量明显小于LITC。SEM见PL变形及被吸附的量均小于LITC。结论心瓣膜置入后第一反应是血浆蛋白优先于PL被吸附,吸附的种类和数量决定于瓣膜的结构与成分,带负电荷的FIG与瓣膜间若存在较大的界面张力,又具有电子强交流,将FIG失去立体构象的稳定,FIGγ肽链C端上的PL结合位点被暴露,PL与FIG联结便发生凝血,与PL活性有关的膜糖蛋白GPⅡb/Ⅲa也取于瓣膜粘附的蛋白。

Objective To learn the rationale of the reaction of blood on the artifical heart valve.Methods Compared the physical and chemical properties,the platelet（PL） adhesion test in vitro,the adsorption of fibrinogen detected by radioactivity of I 125,the PL adhesion evaluated by lactate dehydrogenase,the morphous and the quantity of adhered PL by scanning electron microscope（SEM） of titania（Ti-O） materials imbeded in dog femoral artery for six months of new artifical Ti-O heart valve with current used hydrolytic carbon（LTIC） heart valve.Results The adsorption of PL on Ti-O was less than LITC whether in vivo or in vitro,both the deformities and the adsorption of PL on Ti-O were less than LITC by SEM samely.The interfacial energy of Ti-O was similar to FIG because of its＇N-type semiconductor properties.Conclusion When the artifical heart material was transplanted into heart,the plasma protein was absorbed to the surface of material ahead of FIG.The amount and the type of adhesion plasma protein was different accord to the construction and composition of material.If there was great surface tension between material and FIG with negative charge,and FIG released electron to material,the stereo construction of FIG would be transformed.The action points of FIG were revealed in C termina of its＇γ chain,the PL and the FIG were conjoined,coagulation proceeded at once.Action of PL related to membrane glycoprotein GPⅡb/Ⅲa was concerned to the protien adhered to biomaterial.