Studies on rat complement. I. Immune adherence and immune hemolysis activities of rat serum

The measurement of immune adherence reactivity of rat complement is possible at 20 degrees C but not at 37 degrees C. At 37 degrees C, EA rat C1423b site was destroyed by C3b inactivator present in rat serum. The optimal temperature for immune hemolysis reactivity of rat serum is either at 20 degrees C or 21 degrees C and dose response curve showed Von Krough equation with 1/n = 0.25 +/- 0.02. Al lower temperature, rat complement showed much more effective formation of C3 site to reacti with human erythrocyte in immune adherence as compared with guinea pig complement. The measurement of immune adherence reactivity of rat complement was not possible due to C3b inactivator at 37 degrees C but possible at 20 degrees C. It is possible due to lowering the reactivity of C3b inactivator and keeping the reactivity to form active C3b site in immune adherence reaction. Rat complement is more effective to make C3 site as compared with guinea pig complement. This explains the reason why EDTA rat serum has known to be most effective source of late acting complement for measurement of C1 and C2.