Modified Establishment Method of a Rat Kidney Allograft Model

Kidney transplantation is an established therapeutic option for patients with end-stage renal disease. However, immune rejection and the adverse effects associated with long-term immunosuppressive therapy remain major challenges affecting graft survival and patient outcomes. With the rapid development of cell therapy, regenerative medicine products, and immunomodulatory agents, reliable and reproducible preclinical animal models are essential for evaluating the safety and efficacy of novel therapeutic strategies. The rat kidney allograft model is a valuable platform for studying acute and chronic rejection, antibody-mediated rejection, immune regulation, and transplant tolerance. This study aimed to establish a standardized rat kidney allograft model and surgical workflow for future preclinical evaluation of immunosuppressive drugs, cell therapy products, and other immunomodulatory interventions. In methods, Sprague-Dawley rats were used as donor and recipient animals. A standardized surgical procedure was established, including donor kidney procurement, renal artery and vein preparation, ureteral catheterization, heparinized saline perfusion, cold preservation of the donor kidney, recipient kidney transplantation, vascular reperfusion, ureteral reconstruction, and postoperative care. General anesthesia, analgesia, aseptic surgical procedures, and postoperative monitoring were incorporated into the protocol. Potential outcome measures for future efficacy studies were also proposed, including graft function, histopathological changes, immune cell infiltration, inflammatory cytokines, and graft survival. In results, a complete rat kidney allograft surgical workflow was successfully established, including donor nephrectomy, graft perfusion, vascular and ureteral reconstruction, reperfusion assessment, and postoperative care. Successful reperfusion was evaluated by immediate color change of the graft, restoration of renal perfusion, ureteral peristalsis, and possible urine production. The model provides a practical platform for assessing graft function, immune rejection, inflammatory responses, and therapeutic effects of immunomodulatory products. In conclusion, the rat kidney allograft model established in this study provides a clinically relevant preclinical platform for investigating transplant rejection, immune regulation, and transplant tolerance. This model may support the development of cell therapy products, immunosuppressive agents, and other immunomodulatory strategies before progression to large-animal studies or clinical trials.