Fig. 1.

Long-term kidney graft functions with and without carbon monoxide (CO) treatment on days 60–150. Sequential analysis of creatinine clearance (CCr; A) and urinary protein amounts (B) revealed progressive deterioration of the allograft functions in air-treated controls (▪, n = 16). In contrast, treatment with inhaled CO (20 ppm on days 60–150) improved allograft functions (○, n = 18). Isograft maintained normal functions for 150 days (•, n = 7). *P < 0.05 air vs. CO. Recipient survival (C) suitably correlated to renal graft functions. While all isograft recipients survived for >150 days (n = 7), all air-treated control allograft recipients (n = 16) died of renal insufficiency within 150 days. CO inhalation treatment initiated at day 60 significantly improved recipient survival, and 11 of 18 recipients survived for >150 days [*P < 0.05, air-treated vs. CO (20 ppm) on days 60–150].