In vivo decomplementation of guinea pigs with cobra venom factor and anti-C3 serum: analysis of the requirement of C3 and C5 for the mediation of endotoxin-induced death

Abstract

Guinea pigs were decomplemented by administration of cobra venom factor and goat anti-C3 serum in order to determine whether endotoxin-induced death could be prevented. The combined use of both reagents resulted in the complete elimination of all serum C3 and C5 hemolytic activity. This yielded, however, a shortened rather than extended longevity following endotoxin challenge. The mixing of endotoxin in vitro or in vivo with serum of animals already partially depleted of C3 resulted in no further activation of this component, further suggesting that the interaction of complement with endotoxins does not relate to mortality in animals following endotoxin challenge. Thus, although it has been demonstrated that complement components aid in the detoxification of endotoxin, the present data show that the C3 and C5 components are not mediators of endotoxin-induced death.