Surgical stress during operation for gastrointestinal cancer increases plasma thioredoxin levels and decreases mitochondrial membrane potential in peripheral blood lymphocytes

Abstract

Surgical stress is difficult to evaluate quantitatively. It has been reported that mitochondrial membrane potential (Δψ_m) in the peripheral blood lymphocytes (PBLs) is decreased by surgical stress. Thioredoxin (TRX), a small protein with redox-active dithiol/disulfide in the active site, is induced by a variety of oxidative stresses and secreted from the cells. Accumulating evidence shows that plasma levels of TRX are elevated in oxidative stress-associated disorders. In the present study, we examined plasma levels of TRX in cases undergoing operations for gastrointestinal cancer. Plasma levels of TRX were significantly elevated on the first postoperative day compared with the pre-operative levels. The changes in the plasma TRX levels tended to show an inverse relationship with the changes in Δψ_m in PBLs, which shows a significant decrease caused by surgical stress. Plasma TRX levels as well as Δψ_m in PBLs are valuable markers to evaluate surgical stress.