UROCANIC ACID AS AN IMMUNOSUPPRESSANT IN ALLOTRANSPLANTATION IN MICE

Urocanic acid (UCA) was investigated for its activity as an immunosuppressive agent in murine heterotopic allotransplantation. Mice grafted with cornea, pancreas, and skin under the renal capsule were given either intravenous, subcutaneous, or topical cis-UCA in the peritransplant period. Grafts were performed across complete and minor MHC barriers. Peritransplant immunosuppression with cis-UCA prolonged survival of these grafts, but no route of administration was clearly superior to another. Survival of cornea was prolonged more than survival of skin or pancreas in all MHC disparate combinations. cis-UCA was also used to assess its effect on stimulator cells, derived from mice that had received UCA, in mixed lymphocyte responses. cis-UCA adversely affected the ability of stimulator cells to provoke T cell proliferation in an allogeneic MLR. These findings suggest that cis-UCA may be a potentially useful immunosuppressive agent.