[The change of lymphocyte subset and effect of FK506 in experimental small bowel transplantation of rats].

I analyzed the relationship of the change of lymphocyte subsets in the blood and acute allograft rejection of heterotopic small bowel transplantation in the rats. The effect of immunosuppressive agent, FK506 was monitored by lymphocyte subsets and effective dose in small bowel transplantation was assessed. Four different combinations were investigated: (A) syngenic graft; (B) allogenic graft without FK506; (C) allogenic graft with FK 0.135mg/kg/day; and (C-2) allogenic graft with FK 0.270mg/kg/day. Lymphocytes obtained from the caudal artery blood at 1, 3, 5 and 7 days after transplantation, were stained by monoclonal antibodies (W3/13, W3/25, OX-8, 68-IB3) and then enumerated by flow cytometry. In group A, lymphocyte subsets showed no significant change after transplantation. Group B showed remarkable decrease of W3/13 and OX-8 positive cells at 3 and 5 days after transplantation. In group C-1, the change of lymphocyte subsets was similar to group B. In group C-2, the lymphocyte subsets revealed almost same change as group A. The change of lymphocyte subsets, especially W3/13 and OX-8 positive cells, may be useful marker for early diagnosis of acute rejection and for determination of the effective dose of FK506 in the small bowel transplantation.