F. The relation of complement to other systems: The relations of complement to the other systems

One part of the topic assigned to me is simple to discuss. So far as I am aware, there are no known or suggested interactions of complement with the renin-angiotensin system. There are, however, a number of relations of complement to the permeability globulin (kinin forming), clotting and fibrinolytic enzymes which have been established or have been postulated on the basis of greater or lesser degrees of evidence. I shall address myself first to the relations which are more or less well defined. These are the possession by complement and the permeability globulins of a common inhibitor, C'1 esterase inhibitor; the effects on the clotting mechanism caused by complement mediated allergic damage to platelets, and the several proteolytic effects of plasmin on the complement system. Complement, platelets and plasminogen are all involved in the lysis of human blood clots (Taylor & Müller-Eberhard 1967). A relation of complement to the lysis and to the other factors has been suggested but not proved.