Acute hemorrhagic pancreatic necrosis in mice: lack of a pathogenetic role for complement

Feeding a choline-deficient diet containing 0.5% DL-ethionine induces an acute hemorrhagic pancreatitis in 100% of young female mice. Evidence for deposition of the third component of complement (C3) on acinar cell plasma membranes was sought, during the inductive stages, by a sandwich immunofluorescence technique. Such a localization could not be demonstrated even though the method is capable of detecting less than 8 x 10(-5) microgram of protein/mm2 of cell membrane. Artifactual binding of immunoglobulin reagents was encountered when goat antisera, with high levels of circulating immune complexes, formed the middle layer in the sandwich technique. This was attributed to the appearance of Fc receptors on the plasma membrane of degenerating acinar cells, and could be avoided by ultracentrifuging acinar cells, and could be avoided by ultracentrifuging the goat antisera prior to sue. In view of the fact that C3 cleavage represents an amplification loop in both the calssical and alternate pathways of complement activation, the lack of demonstrable C3 staining in tbe present experiments strongly suggests that complement plays no role in acinar cell necrosis in this model of pancreatitis.