Inagaki M, Goto K, Katayama H, Benson K T, Goto H, Arakawa K
Department of Anesthesiology, University of Kansas Medical Center, Kansas City 66103.
J Cardiothorac Anesth. 1989 Dec;3(6):734-6. doi: 10.1016/s0888-6296(89)94896-5.
A protamine titration is one of the methods to determine the protamine dose necessary to neutralize heparin. The protamine dose response was studied with the activated partial thromboplastin time (APTT) in the presence of a known amount of heparin and in the absence of heparin, using freshly prepared human plasma. When heparin was present in the plasma, APTT values plateaued between a minimal neutralizing dose of protamine and a protamine dose five times greater. At doses above the APTT plateau, protamine exerted its own anticoagulant action as evidenced by an increase in APTT values. In the absence of heparin, APTT did not change until the protamine concentration reached 50 micrograms/mL. Then the APTT began to increase above this critical concentration. The increases in APTT values caused by an increase of 50 micrograms/mL of protamine were significantly greater without heparin than they were in the presence of heparin. These results suggest that protamine has a wide safety range when neutralizing heparin without exerting its own anticoagulant action. Although the mechanisms are under speculation, the heparin-protamine complex may inhibit the anticoagulant action of protamine in vitro.
鱼精蛋白滴定是确定中和肝素所需鱼精蛋白剂量的方法之一。使用新鲜制备的人血浆，在存在已知量肝素和不存在肝素的情况下，通过活化部分凝血活酶时间（APTT）研究鱼精蛋白剂量反应。当血浆中存在肝素时，APTT值在最小中和剂量的鱼精蛋白和五倍于此剂量的鱼精蛋白之间达到平稳。在高于APTT平稳期的剂量下，鱼精蛋白发挥其自身的抗凝作用，表现为APTT值升高。在不存在肝素的情况下，直到鱼精蛋白浓度达到50微克/毫升，APTT才会改变。然后在这个临界浓度以上APTT开始升高。每增加50微克/毫升鱼精蛋白导致的APTT值升高在无肝素时比有肝素时显著更大。这些结果表明，鱼精蛋白在中和肝素时具有较宽的安全范围，且不会发挥其自身的抗凝作用。尽管其机制尚在推测中，但肝素-鱼精蛋白复合物可能在体外抑制鱼精蛋白的抗凝作用。
