[Immune tolerance induced by combined heart-thymus transplantation with intrathymic inoculation of thymocytes in rats].

To explore the role of allo heart and thymus transplantation by intrathymic inoculation of thymocytes.Wistar recipients were given intrathymic injection of allo thymocytes (2 x 10(7)) 14 days before the heart and/or thymus transplantation. Graft survival, histopathology, levels and mRNA expressions of IL-2, IL-4 in serum and cardiac-grafts were investigated.Heart transplantation and heart-thymus composite transplantation with the treatment of CysA for 7 or 14 days prolonged graft survival. Heart transplantation and heart-thymus composite transplantation with intrathymic thymocytes injection induced the long-term survival of allo-grafts transiently immunosuppressed with CysA; IL-4 maintained at high levels but IL-2 kept at low levels in grafts in long-term survivals.Intrathymic inoculation of allo thymoctyes can induce immune tolerance for both cardiac transplantation and heart-thymus combined transplantation in rats. Thymus graft may play a role in the induction and maintenance of central tolerance.