Summary
The effects of a number of synthetic arginyl- and lysyl-compounds on clotting and
fibrinolysis have been studied. The lysyl derivatives had no significant effect on
the clotting of recalcified plasma or recalcified euglobulin preparations, but tosyllysine
(TL) and tosyllysine methyl ester (TLME) were very effective inhibitors of fibrinolysis.
Certain arginyl-peptides (in particular, tosylarginylsarcosine methyl ester) were
very effective at delaying clotting in these systems. These same substances gave rise
to an exaggerated thrombin production, however, evidently by interfering with the
natural thrombin activation of plasma antithrombin(s).