Chen L B, Buchanan J M
Proc Natl Acad Sci U S A. 1975 Jan;72(1):131-5. doi: 10.1073/pnas.72.1.131.
When added to a culture medium of resting confluent chick embryo fibroblasts in the absence of serum, thrombin (EC 3.4.21.5) is able to stimulate DNA synthesis 12 hr later and to cause a substantial increase in cell number over a period of 4 days. As compared to thrombin, prothrombin exhibits low mitogenic activity. However, in the presence of purified Factor Xa (EC 3.4.21.6) and Factor V, prothrombin is converted to thrombin by "thromboplastin activity" supplied by the fibroblasts. Prothrombin, either purified or as a constituent of plasma or serum, may thus be considered to be a reservoir of mitogenic activity in tissue culture unless antithrombin is present in the culture medium in amounts sufficient to neutralize the thrombin formed. By use of a specific inhibitor of proteases, and by separation of prothrombin by absorption on BaSO4, we estimate that the potential mitogenic activity of prothrombin is approximately 30-50% of the total activity that can be obtained by treatment of fibrinogen-free plasma with thromboplastin. In addition to its mitogenic activity, thrombin can also stimulate the migration of cells. These experiments with thrombin illustrate that well-characterized proteases of blood can act as potent mitogens and suggest that they may play a role in the process of wound healing.
在无血清条件下，将凝血酶（EC 3.4.21.5）添加到静止汇合的鸡胚成纤维细胞培养基中，12小时后它能够刺激DNA合成，并在4天内使细胞数量大幅增加。与凝血酶相比，凝血酶原的促有丝分裂活性较低。然而，在纯化的因子Xa（EC 3.4.21.6）和因子V存在的情况下，凝血酶原通过成纤维细胞提供的“凝血活酶活性”转化为凝血酶。因此，纯化的凝血酶原或作为血浆或血清的成分，除非培养基中存在足以中和所形成凝血酶的抗凝血酶，否则可被视为组织培养中有丝分裂活性的储存库。通过使用蛋白酶的特异性抑制剂，并通过硫酸钡吸附分离凝血酶原，我们估计凝血酶原的潜在有丝分裂活性约为用凝血活酶处理无纤维蛋白原血浆所能获得的总活性的30%-50%。除了其有丝分裂活性外，凝血酶还能刺激细胞迁移。这些关于凝血酶的实验表明，血液中特性明确的蛋白酶可以作为有效的有丝分裂原，并表明它们可能在伤口愈合过程中发挥作用。
