[The unaffected primary rejection of xenogeneic kidney transplants in the closely related fox-dog species system].

The present study reports of three kinds of experiments of unaffected primary rejection of xenogenous kidney transplanats in the close-related fox-dog species system. The issue is whether there is a relation between the amount of grafted parenchyma and the immune induced potency, that is whether the course of rejection of transplanted single kidneys (group I a) differs from the course after en-bloc transplantation of both kidneys (group I b). In group II alterations of blood chemism and behavior of humoral antibodies are followed in dogs to which a fox kidney was transplanted, while keeping their own functioning kidneys. This experiment is to give information whether the uremic syndrome influences the development of humoral immunity, and what changes of blood chemism may primarily be related to destruction of the graft, under the condition of absent uremia. Untreated graft recipients survived for 5,4 +/- 0,49 days (n = 5) when single kidneys were transplanted (group I a), and 5,2 +/- 0,75 days (n = 5) when both kidneys were grafted en-bloc (group I b). As to the rejecting reactions, both groups are almost equal: the increasing functional failure causes a fast increase of creatinine and urea nitrogen; alkaline phosphatase and LDH show distinct alterations, related to the progress of the graft's destruction. Decrease of albumin level and loss of cholinesterase activity indicate an impaired hepatic function as reaction to uremic intoxication. Gamma-globulins and leucocytes show alterations that can be related to non-specific inflammatory reactions. The immunologically specific initial lymphopenia suggests that after revascularization these cells migrate to the graft, and later react with antigenic structures of vascular endothelium and still later with those of the organ cells. Cytotoxic antibodies appear on the 4th postoperative day in increasing amount. Post mortem histologic examination shows round cell infiltrates in the vastly necrotic renal parenchyma. When the recipient's kidneys are kept in situ and a fox kidney is transplanted (group II) uremia is avoided and the animals survive. During the 30-days period of observation, that is longer than the term of rejection, the titer of cytotoxic antibodies remains stable or tends to increase. LDH and alkaline phosphatase show characteristic changes that are considered sequels from destructed transplantate. The experiments show, aside from certain reservations, that the donor-host combination fox-dog is suitable to serve as preclinic model for human transplantation using xenogenous donors of organs, i. e. anthropoid primates.