The Role of Fibronectin in Arterial Subendothelium in Platelet Adhesion

The role of fibronectin in vascular subendothelium in platelet adhesion after the removal ofthe endothelium of aorta was studied in normal rabbits. The thoracic aortae were treated with 1%Nonidet P-40 for 5 min and with 0. 3 mol/L KCl for 10 min. The whole endothelium was re-moved and a large amount of fibronectin in the subendothelium was exposed. Autogenous platelet-rich plasma was isolated and platelets were labeled with 1:1000 acridine orange. The adheredplatelets were washed away with 2% SDS solution. Finally, the intensity of fluorescence of the wash-ing fluid was measured with a spectrofluorophotometer. The animals were divided into 4 groups:(1) normal endothelium group. (2) lysed endothelium group, (3) lysed endothelium and guineapig anti-rabbit fibronectin antisera inhibition group, (4) lysed endothelium and guinea pig normalsera control group. The adhesion of platelets in the 2nd group was taken as 100%. The resultsshowed that after the treatment of anti-rabbit fibronectin antisera the platelet adhesion onsubendothelium was inhibited up to 70. 1%. It is suggested that the fibronectin in subendotheliumplays an important role in platelet adhesion.

Von Willebrand因子在血小板粘附中的扫描电镜观察

本文应用抗人von Willebrand因子(vWF)单克隆抗体SZ—29和扫描电镜,观察了血管内皮下层及血浆vWF在血小板与血管壁粘附中的作用。当内皮细胞剥脱后,血管壁表面有大量血小板粘附;当用SZ—29单抗阻断血管内皮下层或血浆vWF作用时,血管壁仍有大量血小板粘附;当血管内皮下层及血浆vWF同时被阻断,则血管壁上粘附的血小板显著减少(P<0.005),表明血管内皮下层和血浆vWF在血小板与血管内皮下层粘附中均起重要作用。

Von Willebrand因子分布的免疫组织化学研究

本文用抗人von Willebrand因子(vWF)单克隆抗体SZ-29,采用免疫金银法和ABC法,研究了vWF在血管、血小板的分布情况。结果显示,vWF分布于腹主动脉,脐动脉和脐静脉的内皮,内皮基膜区、内皮下层及中膜内区,且vWF特异染色以内皮、内皮基膜区染色最深。免疫金银法显示大部分血小板vwF特异银染呈颗粒状分布,约3—5％血小板整体胞体呈现银染。而免疫电镜观察,静止型血小板vWF分布于α-颗粒内,血小板膜没有或极少结合的vwF;激活型血小板,除α-颗粒外,vWF结合于血小板膜及开放管道系统膜上,在血小板伪足,尤其是伪足末端,常呈现vWF特异染色。