Abstract: | Abstract. Experimental evidence suggests that jejunal allografts are rejected as rapidly as are ileal grafts, despite their lesser content of lymphoid tissue as an immunologic stimulus. However, it may be possible to postpone the rejection of jejunal grafts more readily than that of ileal grafts by means of immunosuppressive therapy with cyclosporin (CyA). To test this, we used the rat model (BN-LEW) of orthotopic small-bowel transplantation. The proximal third of the small-bowel with one-third of the mesenteric lymph nodes (n= 20), or the distal ileal third with all of the mesenteric lymph nodes (n= 22), or the entire small-bowel (n= 23) was interposed after resection of an equivalent type and length of recipient bowel. CyA (15 mg/kg) was given to all of these rats for 5 days. Three additional control groups were not given CyA. The difference in graft/recipient survival among the groups receiving CyA and among those not on CyA therapy was not statistically significant. Antidonor hemagglutinin titers, the mixed lymphocyte culture (MLC) assay, and histologic examination of the allograft failed to show a mitigated rejection reaction for the recipients of jejunal grafts. The data show that short-term treatment with CyA prolongs graft survival. Equal doses of CyA, however, did not lead to prolonged survival of jejunal grafts or alter the course of rejection in comparison with that for ileal or whole-bowel transplants. |