Lowenthal J, Birnbaum H
Science. 1969 Apr 11;164(3876):181-3. doi: 10.1126/science.164.3876.181.
Coumarin anticoagulants inhibit the release of plasma clotting factor VII by vitamin K in liver slices from vitamin K-deficient animals without inhibition of protein synthesis. When the ratio of vitamin K to coumarin anticoagulant is kept constant, but the concentrations are increased, the inhibition disappears. This suggests that the pharmacological action of coumarin anticoagulants depends on irreversible inhibition of normal vitamin K transport to its site of action. At higher concentrations of vitamin K the inhibition can be surmounted, because vitamin K can enter the cell by an alternate route that is not inhibited by coumarin anticoagulants.
香豆素类抗凝剂可抑制维生素K缺乏动物肝脏切片中维生素K诱导的血浆凝血因子VII的释放，而不抑制蛋白质合成。当维生素K与香豆素类抗凝剂的比例保持恒定，但浓度增加时，抑制作用消失。这表明香豆素类抗凝剂的药理作用取决于对正常维生素K转运至其作用位点的不可逆抑制。在较高浓度的维生素K作用下，这种抑制作用可以被克服，因为维生素K可以通过一条不受香豆素类抗凝剂抑制的替代途径进入细胞。
