The free amino acid changes in plasma following coagulation and plasminogen activation.

By SAui I. COHEN A RECENT REPORT1 from this laboratory describes increases in certain of the tinbound amino acids and the appearance of a peptide after recalcification and subsequent coagulation of human blood plasma. It has been suggested2 that activation of plasminogen ( profibrinolysin ), the inactive enzyme precursor of the blood protease plasmin ( fibrinolysin ) , is accelerated during the process of coagulation. Thus, release of “small molecules” subseqtient to plasma clotting1 may be attributable, in part at least, to the effects of the activated fibrinolytic system. To test this hypothesis, the release of unbound amino acids after streptokinase activation of the plasminogen in human blood plasma and during digestion by plasmin of a purified preparation of fibrinogen was studied.