The effect of anticoagulants on postoperative fibrinogen metabolism. Secondary anaemias, XVI.

. Studies of the effects of dicoumarol and heparin on the metabolism of radioactively labelled fibrinogen given to elderly injured patients subjected to reparative surgery showed that: 1) The actual amount of labelled protein (mg/kg) synthesized and catabolized per day was approximately three times normal, irrespective of whether therapy included or excluded dicoumarol or heparin. The increased rate of synthesis of fibrinogen leads to the observed increased plasma concentrations of fibrinogen. 2) The amount of radioactivity outside the active circulation was increased both in the patients treated with dicoumarol or heparin and in those given no anticoagulants. Similarly, the radioactivity in the operated legs was often higher than in the uninjured legs irrespective of whether anticoagulant had been administered or not. The radioactivity outside the active circulation had a longer biological half-life than that of the plasma fibrinogen, suggesting that at least some of the non-circulating radioactivity was attached to fibrin even in the patients receiving heparin. The increased rate of synthesis of fibrinogen leads to the observed increased plasma concentrations of fibrinogen.