OXIDIZED GLUTATHIONE AS A MARKER OF ISCHEMIA-REPERFUSION ASSOCIATED WITH SINGLE-LUNG TRANSPLANTATION

BACKGROUND: Previous data have shown that glutathione (GSH), an endoge nous antioxidant, is converted to its oxidized form (GSSG) after oxida tive ischemia-reperfusion events. As GSSG is toxic to cells and is ext ruded through an active mechanism dependent on intracellular GSSG leve ls, substance appears in plasma.STUDY DESIGN: Single lung transplantat ion was performed upon 18 puppies, 3 to 5 kg, with a two hour ischemic time for the donor lung before reimplantation. Recipient animal plasm a was obtained after anesthesia induction, pulmonary artery ligation, recipient pneumonectomy, reestablishment of blood flow to the donor lu ng, completion of transplant, and one, two, and three hours postoperat ively. Donor lung bronchoalveolar lavage fluid (BALF) was obtained at the time of harvest, after perfusion of the donor lung with EuroCollin s, immediately pretransplant, and after completion of the vascular ana stomoses. Oxidized and total GSH levels in plasma and BALF samples wer e determined by a spectrophotometric assay. RESULTS: After reimplantat ion of the ischemic donor lung, there was a statistically significant increase in both GSSG and GSH in plasma samples, and a statistically s ignificant increase in GSSG in the BALF. CONCLUSIONS: Compartmental di fferences between arterial and venous plasma, as well as the increase in GSSG in the BALF, implicated the lung that was transplanted as the source of oxygen free radical generation and GSSG release. Plasma GSSG levels seem to provide a sensitive, noninvasive, repeatable measure o f ongoing tissue response and oxygen free radical production.