Constant intrarenal infusion of PGE1 into a canine renal transplant using a totally implantable pump.

A method was devised whereby PGE1 could be administered to a canine renal transplant recipient on a chronic basis. PGE1 was stored in the reservoir of an implantable pump and delivered continuously in high doses directly into the renal transplant artery. In the model studied a contralateral untreated transplant from the same donor served as a control. Sequential renal scans were used to study the effect of intraarterial PGE1 on the rejection process. Continuous delivery of PGE1 into the renal transplant artery did not prevent allograft failure under these conditions; blood flow diminished similarly in both PGE1-treated and untreated transplants. There were, however, striking differences in the histologic appearance of treated and untreated transplants. PGE1 perfusion resulted in the appearance of large numbers of polymorphonuclear leukocytes but few lymphocytes. In the untreated control allograft, however, the findings were typical of lymphocyte-mediated acute rejection. The distinctive differences noted histologically suggested that the local administration of PGE1 influenced the mechanism by which graft failure occurred. The ability to manipulate cell populations infiltrating an allograft represents a potentially important means for modifying the immune response.