Impaired recoloration of a discordant liver xenograft in the guinea pig-to-rat combination - Physiological, insults or immunological responses

Background The aim of this study was to clarify, using guinea pig (GP) syng eneic and xenogeneic liver graft models, the mechanisms of impaired recolor ation caused by immunological responses or physiological insults; and to ex amine the effect of an anti-complement agent, FC43 emulsion, on xenograft r ejection. Methods and Results. GP syngeneic and xenogeneic liver grafts Bushed with 4 degrees C lactated Ringer's solution were poorly perfused around the porta hepatis, whereas those flushed with 15 degrees C solution were immediately recolored, and the portal venography confirmed homogeneous perfusion throu ghout the GP livers. Impaired recoloration of GP xenografts was also amelio rated by reduction of ischemic time. Pretreatments with FC43 emulsion signi ficantly extended xenograft survivals. Rejected GP Liver xenografts showed C3 deposits on sinusoids and central veins and IgM deposits faintly stained only on some small vessels, but there were no detectable deposits of IgG. Conclusions. The impaired recoloration in this model may be caused by physi ological insults during the initial stage of revascularization, and the imm unological responses that probably followed.