Reperfusion injury following single-lung transplantation: The tissue glutathione response

Abstract

Parenchymal injury following reperfusion of the donor lung remains a significant problem in clinical lung transplantation. It has been postulated that free oxygen radicals act as local mediators of this event, and that tissue oxidized glutathione levels which reflect local free oxygen radical production, may be useful as an indicator of this regional ischemia-reperfusion injury. The glutathione redox cycle plays a physiologically important role in the endogenous antioxidant defense system. Intracellular glutathione depletion has been shown to render cells vulnerable to oxidant mediated injury. Adequate glutathione stores may be vital in protecting the cell from oxidant injury, especially the relatively exposed pulmonary epithelial cells. Single lung transplantation was carried out in 10 3- to 5-kg mongrel puppies, with a standard 2-hour ischemic time for the donor lung prior to reimplantation. Four hours following transplantation, lung tissue was harvested from both the transplanted and native lung of the recipient animal, and compared to normal lung tissue from the donor animal. Tissue was prepared for histological evaluation and glutathione assay. Tissue glutathione levels were determined via a spectrophotometric assay. For determination of oxidized glutathione (GSSG), samples were prepared with 2-vinylpyridine and N-ethylmaleimide (NEM) to derivatize all reduced glutathione and leave only GSSG for measurement by the fluorometric assay.(ABSTRACT TRUNCATED AT 250 WORDS)