Xenon treatment prolonged the allogeneic grafts survival. Xenon treatment (70% xenon balanced with 30% oxygen) was given either to Fischer donor animals before organ retrieval (XD) or Lewis recipient immediately after engraftment (XR). Grafts were kept in 4°C Soltran preserving solution (cold ischemia; CI) for 16 h. Donor or recipient exposed to nitrogen (70% N₂ balanced with 30% O₂) served as treatment control. Contralateral kidney was removed 4 days after transplant surgery. Allograft recipient received cyclosporin A (5 mg/kg) for 10 days. (A) Histology of renal graft on Day 20 after transplant surgery. (B) CD3⁺T cells assessed by immunohistochemistry on Day 20 after transplantation. Kaplan–Meier survival analysis of recipient animals in Fischer-to-Lewis allografts. Xenon gas was given to donor Fischer animals (C) before organ retrieval or to recipient immediately (D) after engraftment (n = 10). Scale bar: 50 μm.