Contact and Plasmin Kinin-Forming Systems in the Blood

Abstract

SummaryBy means of preparations of two different kininogens, the existence of two kallikreins, postulated previously, that is one activated by the contact factor – contact kallikrein, and another by plasmin – plasmin kallikrein, has been confirmed.Stasis plasma or plasma from blood taken without stasis incubated at 37 ° C can be a source of contact kallikrein.It was found that modified plasma, that is plasma acidified to pH 2 and realkalized after 10 min, is suitable material for demonstrating that plasmin activates plasmin kallikrein. Plasmin kallikrein in the plasma has two substrates: kininogen – from which it releases kinins, and contact kallikrein which it inactivates. A diagram showing the activation of kinin-forming systems in the blood plasma is proposed.

Cold Promoted Activation of Factor VII

“…Many authors have observed the activation of prekallikrein by plasmin (Back et al 1963;Buluk et al 1970;Vogt 1964;Webster and lnnerfield 1965), and activation of plasminogen by plasma kallikrein has also been reported (Colman 1969). The effects of plasmin on the plasma coagulation system are multiple (Jung and Duckert 1960) and factor VII probably can be activated by plasmin (Godal and Theodor 1965).…”