Beagle

to evaluate the significance ofimmunogenetic factors on the survival of pancreatic allografts in beagle dogs. Donors and recipients were leukocyte antigen (DLA)-typed and mixed lymphocyte culture (MLC)-tested. Recipients were made diabetic by total pancreatectomy and immediately implanted intraperitoneally with a vascularized, free-draining (duct unligated) pancreatic segmental (FDPS) allograft. Two groups of dogs were studied. In group I consisting of donor-recipient litter-mates, recipients were immunosuppressed with pred-nisone and azathioprine (n = 16 dogs), or not immuno-suppressed (n = 4). In group II, recipients were made specifically unresponsive by total body radiation, autol-ogous marrow implantation, and kidney transplanta-tion from DLA-MLC identical donors, 1 yr before FDPS transplantation from the corresponding original kidney donors. Survival of the FDPS grafts in group I was inversely related to pretransplant MLC reactivity, irrespective of DLA genotyped match between donor and recipient. Thus, immunosuppressed high MLC reactors (n = 8) rejected FDPS grafts between 7 and 14 d, whereas im-munosuppressed low MLC reactors (n = 8) accepted grafts for 25 to 260+ days, and nonimmunosuppressed low MLC reactors (n = 4) accepted grafts for 9-55 d. Rejection (hyperglycemia) of FDPS grafts was sudden, permanent, and unpredictable despite weekly intra-venous glucose tolerance tests with measurements of glucose disappearance rates and serum insulin re-sponses. Nevertheless, serial in vitro cell-mediate