The effect of immunosuppression on function of kidney allografts in the rat

Transplantation of living tissues is not a new concept. Greek mythology presents us with the Chimera in which a goat's body, a lion's head and a dragon's tail are joined to form a terrifying monster. Ancient Indian surgeons made use of local skin flaps for rhinoplasty, an art which has been practiced in Italy as early as the fifteenth century. Various transplantation experiments were performed by John Hunter in the eighteenth century. However, a systematic approach to the study of transplantation biology has only been started during the present century when technical progress in the field of surgery (Carrel and Guthrie 1905, 1906; Carrel 1908) made it possible to transplant a large variety of tissues and organs. Unfortunately, surgical problems are not the only obstacles to successful transplantation. lt has been known for a long time that tissue transplants in which the donor is also the recipient (autografts) or transplants between animals of the same inbred strain (isografts) will survive. Without complications this also applies to grafts between identical twins. On the other hand, transplants between two randomly chosen individuals of the same species called homografts or allografts, behave like autografts for a few days only, after which progressive damage occurs, leading to loss of function and destruction of the graft. This process, called rejection, is usually complete within a few weeks following transplantation and is invariably accompanied by infiltration with inflammatory cells, predominantly of the mononuclear type. In transplants exchanged between members of different species (heterografts, syn. xenografts), a much more violent and rapid rejection may take place.