Effect of ribonucleic acid perfusion on canine kidney and liver homograft survival.

M any of tho probl,n~ of o'gall tran,plantation could be minimized if it were possible to mitigate graft rejection by modifying the transplanted tissue rather than the host immunologic response. Efforts to achieve this objective have been unsuccessful, with occasional possible exceptions,4, 9, 11 of which the most intriguing was described by Jolley, Hinshaw, and PetersonY They reported that rabbit skin grafts which were first immersed in homologous ribonucleic acid (RNA) and then transplanted to recipient animals which were given intravenous RNA had a survival 4 times longer than controls. The role of the preliminary soaking was not analyzable in these experiments, but the authors also reported that human skin homografts subjected only to RNA soaking had unusually protracted viability when placed upon patients with burns.'o Similar attempts to "pretreat" whole organ homografts have so far been unsuccessful. 21 In our experiments, this concept has been