Presumed and actual concentrations of reduced glutathione in preservation solutions

Reduced glutathione (GSH), an important radical scavenger, has been added to various organ preservation solutions. Because GSH oxidizes into oxidized glutathione (GSSG) and only GSH has scavenging capacity, only GSH in the solution at the time of clinical use is relevant. The concentrations of GSH (GSH(conc)) and GSSG(conc) were determined in 2 static preservation solutions--University of Wisconsin (UW) and Celsior--and in 1 machine preservation solution--Kidney Preservation Solution 1 (KPS-1). We determined the half-life (T(1/2)) of freshly added GSH. The GSH(conc) in UW and KPS-1 was 0.006 ± 0.0018 mmol/L and 0.13 ± 0.30 mmol/L, respectively. The GSH(conc) in Celsior was 2.7 ± 0.17 mmol/L. The manufacturers of these solutions reported 3 mmol/L GSH. GSSG(conc) in UW, KPS-1, and Celsior was 1.58 ± 0.61 mmol/L, 1.13 ± 0.16 mmol/L, and 0.24 ± 0.01 mmol/L, respectively. T(1/2) of GSH in UW, KPS-1, and Celsior was 18 days, 86 days, and 83 days, respectively. The actual GSH(conc) in UW and KPS-1 at the time of clinical use was substantially lower than reported by the manufacturer, owing to the relatively short T(1/2) of GSH. For Celsior, the GSH(conc) was maintained. Therefore, addition of fresh GSH to UW and KPS-1 before clinical use is recommended.