The effect of donor-specific transfusion and cyclosporin A on small bowel transplantation in the rat.

Pre-transplant blood transfusions are given as a means of desensitization to reduce the required dose of cyclosporin A (CsA). In this study, the effect of pretransplant blood transfusion on host survival and T-cell function against alloantigen were investigated. Male Lewis rats (RT1(1)) were used as the recipients in all experiments, and male DA rats (RT1a) were used as the blood and small bowel donors, and as a source of allogeneic stimulator cells. Male BUF rats (RT1b) were used as donors of third party blood, and of allo-stimulator cells in a delayed-type hypersensitivity (DTH) response. In our experimental design, Lewis rats were divided into the following groups according to the type of administration: (1) a donor-specific blood transfusion (DST) 8 days preoperatively and a concurrent 5-day course of CsA at 10 mg/kg per day; (2) a nonspecific third party blood transfusion (NST) and CsA at 10 mg/kg per day from day 8 to day 4 preoperatively; (3) CsA alone from day 8 to day 4 preoperatively; (4) DST alone 8 days preoperatively; or (5) no treatment, being the control group. Postoperative treatment consisted of CsA at 2.5 mg/kg per day for 30 days. Rats conditioned with NST plus CsA, CsA alone, DST alone, and the untreated control rats survived for 7.2 +/- 1.2, 9.0 +/- 2.2, 6.8 +/- 0.4, and 7.4 +/- 1.6 days, respectively. In contrast, the five rats conditioned with DST plus CsA survived for 100 days or more.(ABSTRACT TRUNCATED AT 250 WORDS)

Heterotopic sternum transplant in rats: A new model of a vascularized bone marrow transplantation.

We introduced the heterotopic vascularized sternum transplant as a more simple and pure alternative to allogeneic hind limb transplantation for the study of bone marrow transplantation. We report the clinical and histopathological manifestations after transplantation of syngeneic and allogeneic sternal grafts with and without immunosuppression with FK-506. Syngeneic grafts maintained normal histology, whereas allografts showed rejection, which was prevented by FK-506. FK-506-treated allografts developed chimerism that was present throughout the observation period. Transplantation of the sternum may be a valuable model to study vascularized bone marrow transplantation and its effects on repopulation of bone marrow of the host, chimerism, and tolerance.