Le D T, Borgs P, Toneff T W, Witte M H, Rapaport S I
Department of Pathology, University of California, San Diego, La Jolla 92093-0612, USA.
Am J Physiol. 1998 Mar;274(3):H769-76. doi: 10.1152/ajpheart.1998.274.3.H769.
Mechanisms regulating extravascular coagulation in interstitial fluids of peripheral tissues are poorly understood, since measurements of hemostatic factors in these fluids are unavailable. Because lymph from a body region reflects the composition of its interstitial fluid, we measured hemostatic factors in limb lymph of rabbits both as activity and as antigen. Mean lymph-to-plasma activity ratios were the following: fibrinogen, 0.28; prothrombin, 0.26; factor X, 0.27; factor VII, 0.17; and factors V and VIII, 0.08. All lymph fibrinogen was clottable; fibrin degradation products were absent. Lymph von Willebrand factor antigen was < 10% of plasma antigen and consisted primarily of lower molecular weight multimers. Mean lymph-to-plasma activity ratio for antithrombin was 0.38 and for tissue factor pathway inhibitor the ratio was 0.40. Low levels of antithrombin-factor Xa were measurable in lymph. The data are compatible with a basal factor VIIa-tissue factor-catalyzed extravascular activation of factor X that is prevented from progressing to generation of fibrin in limb interstitial fluid and lymph by low levels of factor VIII and factor V and by the inhibitory activity of antithrombin and tissue factor pathway inhibitor.
由于无法测量外周组织间质液中的止血因子，调节外周组织间质液血管外凝血的机制目前仍知之甚少。由于来自身体某一区域的淋巴液反映了其间质液的成分，我们对兔肢体淋巴液中的止血因子进行了活性和抗原测定。淋巴液与血浆的平均活性比值如下：纤维蛋白原，0.28；凝血酶原，0.26；因子X，0.27；因子VII，0.17；因子V和因子VIII，0.08。所有淋巴纤维蛋白原均可凝；不存在纤维蛋白降解产物。淋巴血管性血友病因子抗原低于血浆抗原的10%，主要由低分子量多聚体组成。抗凝血酶的淋巴液与血浆平均活性比值为0.38，组织因子途径抑制物的比值为0.40。淋巴液中可检测到低水平的抗凝血酶-因子Xa。这些数据与因子VIIa-组织因子催化的因子X血管外激活相一致，在肢体间质液和淋巴液中，由于因子VIII和因子V水平较低以及抗凝血酶和组织因子途径抑制物的抑制活性，该激活过程无法进展为纤维蛋白的生成。
