Uber den Reaktions-mechanismus der Hemmung der Blutgerrinung durch einige seltene Erden und durch Heparin. II. Uber die Beeinflus-sung der Prothrombinaktivierung durch Trypsin
Dyckerhoff, H.; Torres, I.
Biochemische Zeitschrift 316(1-2): 31-37
1943
ISSN/ISBN: 0366-0753 Accession: 026034496
The formation of throm-bin may take place by the adsorptive activation of the prothrombin or the proteolytic activation of the prothrom-bin. Adsorptive activation takes place only in the presence of the Ca ion, while proteolytic activation is not dependent upon the Ca ion. The dry trypsin preparation used in the expts. is prepared by treatment of an aqueous extract of pancreas with acetone and ether and contains 0.2 Will-statter units of trypsin/mg. Thrombokinase activity, throm-bin content and prothrombin activation are detd. by the methods previously used (Dyckerhoff and Marx, Biochem. Zeitschr., 313: 107, 1942). Study of the influence of heparin and the salts of the rare earths, neodymium, praseodymium, samarium and erbium, upon the clotting system, pro-thrombin-trypsin-plasma shows that heparin does not influence the first phase of blood clotting, but is a powerful antithrombin. The rare earths, in contrast to their antiprothrombin function in the tissue thrombokinase activation, have no effect on the above blood clotting system.