Reversibility of allograft arteriosclerosis after retransplantation to donor strain

The rat aortic transplant model was modified to investigate whether the vascular wall changes on chronic rejection are reversible. DA (RT1a) aortas were first transplanted to WF (RT1a) recipients. The first transplantation was accompanied, as described earlier, by an increase in intimal cellularity and thickness and typical arteriosclerotic changes of chronic rejection in the allograft intima. A second transplantation was made to DA, WF or to (DAxWF)F1 recipients 10 days-2 months after the first transplantation. In all retransplantations performed at any one of the indicated timepoints, the thickness and number of nuclei of the intima continued to increase. These observations demonstrate that, after an initial trigger, allograft arteriosclerosis proceeds and is irreversible despite elimination of histoincompatibility.