Platelet Requirement in the Interaction of the Complement and Clotting Systems

THE study of immunological reactions in rabbits genetically deficient in the sixth component of complement (C6) can provide information about the biological role of the complement system. Since their discovery¹, these rabbits have been found to produce no C6 protein and they can form antibody against it (ref. 2 and review in ref. 3). Furthermore, although the plasma and serum of these rabbits contain the normal coagulation factors, the whole blood clotting time is longer than normal⁴.