保存血液の線維素溶解酵素の消長について

Abstract

Since large amonnts of blood have readily become available for blood transfusions, such undisirable complications as the development of hemorrhagic syndrome are being increasingly noted in the recipients. There are many possible considerations in regard to the etiology of this side-reaction, such as, the dilution of the clotting factors by the infused blood, in which labile factors have lost their activities during storage, the decrease of platelets in the recipient's blood, the intoxcation by citric acid used as an anticoagulant, and the acceleration of fibrinolysis.Of these consideration, several observers have pointed out the activation of the fibrinolytic system during the storage of blood. Therefore, it seems necessary to perform a systemic analysis of plasminogen, plasmin, and antiplasmin in the stored blood.However, there is no evidence of the conversion of plasminogen into its active form during the storage of blood at 0-4°C, and no influence of anticoagulants usually employed in blood bank, such as, ACD solution, EDTA-Na2 solution, or 3.8% citric acid solution, for the activities of the fibrinolytic system with the exception of the very weak antiplasmin action of EDTA-Na2 solution, according to the observations reported here.Furthermore, it is also obvious that the platelets represent the antiplasmin activity and their number decreases rapidly by storage. It follows that in the presence of the enhancement of fibrinolysis in a patient receiving massive blood transfusions, the activity of the stored blood may be relatively weak in regulating the fibrinolytic system in the recipient because of the reduced number of platelets.On the other hand, while ε-aminocaproic acid shows a potent inhibitory action on plasmin, no effect can be detected against the activation of plasminogen to plasmin as determined by the precipitation method using 1M. NaCl (pH 2.0). It will be reasonable, therefore, to administer ε-aminocaproic acid for arresting bleeding tendency due to fibrinolysis occurring after blood transfusion, although it is not necessary to add ε-aminocaproic acid to the anticoagulant solution for blood banking.