Chicken prothrombin, thrombin, and fibrinogen

¹ Department of Physiology and Pharmacology, University of Alberta, Edmonton, Canada

Avian blood coagulation studies revealed the mean one-stage prothrombin time of plasma from 100 chickens, 10 weeks of age, as determined with chicken brain thromboplastin, to be 11.4 seconds, compared with 10–300 seconds found by other workers; the mean prothrombin content was 137% of human prothrombin levels, as determined by the one-stage prothrombin-time technique, but only 53% by the adsorption and elution technique used. Fibrinogen determinations on the same plasma revealed a mean of 346 mg/ 100 ml of plasma, compared with 250–400 for humans. Chicken thrombin was prepared which gave a mean thrombin time on the same, but buffered, plasma of 12 seconds. Coagulation of chicken plasma with chicken thrombin was found to be highly sensitive to variations in pH, being 12 seconds at pH 7.1, but lengthening to over 60 seconds at pH 7.7. Greatly increased clotting times of chicken plasma with bovine thrombin and with rabbit thromboplastin indicated evidence of species specificity.