Transplantation of the small bowel across MHC and non-MHC disparities in the rat.

ABSTRACT

Using congenic strains of rats, the effect on the rejection of small bowel transplants across isolated major histocompatibility complex (MHC) and nonMHC antigenic disparities was examined. The medial survival time of small bowel grafts across MHC differences in the LEW anti-LEW.1N and LEW.1N anti-LEW strain combinations was 14 and 12 days, respectively. The median survival time across the nonMHC antigenic difference in the BN anti-DA.1N strain combination was 20 days, which was significantly longer than the rejection time across the MHC differences (P less than 0.005). Both hemagglutinating and cytotoxic antibodies were produced in all three strain combinations, but the magnitude of the response varied considerably and did not correlate with the time of rejection. In the case of MHC differences, the antibody was directed against both class I and class II antigens, and with the nonMHC difference, the greatest response was directed against the major blood group antigen RT2.