THE FATAL HAEMORRHAGIC DISEASE OF CHICKEN EMBRYOS INJECTED WITH NORMAL ALLANTOIC FLUID

The already known toxicity of normal chicken allantoic fluid (AF) for the embryo itself, or for other chicken embryos has been analysed and found to be due the content of thromboplastic lipo-proteins in the AF. The haemorrhagic syndrome caused by i. v. injection of the embryo with AF is suggested as an experimental model for the study of intravascular clotting and the “defibrination” syndrome. The lethality of the haemorrhagic syndrome could be largely prevented not only by heparin but also by natural inhibitors present in both chicken serum and a variety of mammalian sera. At least one of these inhibitors has been isolated from mammalian sera and identified as the previously described antithrombin III (progressive antithrombin).