Glusa E, Markwardt F
Institute of Pharmacology and Toxicology, Medical Academy Erfurt, GDR.
Biomed Biochim Acta. 1988;47(7):623-30.
The clotting enzyme thrombin induces not only blood coagulation but it also receptor-mediated cellular events. In our studies, thrombin at nanomolar concentrations caused irreversible aggregation of washed human platelets which was inhibited by the naturally occurring tight-binding inhibitor hirudin. Thrombin within the same concentration range caused concentration-dependent transient relaxation of PGF2 alpha-precontracted pig coronary artery ring segments with intact endothelium. The relaxant response was neither affected by indomethacin nor by verapamil and was only slightly inhibited by exposure to calcium-free medium. Methylene blue enhanced the PGF2 alpha-induced contraction and diminished the thrombin-induced relaxation. Hirudin inhibited the relaxant effect of thrombin in a concentration-dependent manner. After removal of the endothelium by mechanical rubbing the thrombin-induced relaxation was absent. The present studies suggest that thrombin generated during coagulation is able to modify the vascular smooth muscle tone.
凝血酶不仅能诱导血液凝固，还能引发受体介导的细胞事件。在我们的研究中，纳摩尔浓度的凝血酶会导致洗涤后的人血小板发生不可逆聚集，这种聚集可被天然存在的紧密结合抑制剂水蛭素所抑制。相同浓度范围内的凝血酶会使完整内皮的猪冠状动脉环段对前列腺素F2α预收缩产生浓度依赖性的短暂舒张。这种舒张反应既不受吲哚美辛影响，也不受维拉帕米影响，仅在无钙培养基中略有抑制。亚甲蓝增强了前列腺素F2α诱导的收缩，并减弱了凝血酶诱导的舒张。水蛭素以浓度依赖性方式抑制凝血酶的舒张作用。通过机械摩擦去除内皮后，凝血酶诱导的舒张消失。目前的研究表明，凝血过程中产生的凝血酶能够改变血管平滑肌张力。
