Mitochondrial membrane potential in density-separated trout erythrocytes exposed to oxidative stress in vitro

Previous literature reports have demonstrated that nucleated trout erythroc ytes in condition of oxidative stress are subjected to DNA and membrane dam age, and inactivation of glutathione peroxidase. The present study was unde rtaken to investigate if mitochondrial membrane potential in stressed condi tions was also influenced. Density-separated trout erythrocyte fractions, o btained using a discontinuous Percoll gradient, were submitted to stress co nditions and the mitochondrial membrane potential was determined by means o f cytofluorimetric analysis after incubation of each subfraction with JC-1, a mitochondrial specific fluorescent probe. The results clearly show that the mitochondrial membrane potential decreased significantly in all erythro cyte fractions, also if the oxidative effect on mitochondria is more severe with increased density (age) of the cell. Ebselen was very effective in pr eventing mitochondrial depolarization in young as well as in old erythrocyt es. (C) 2001 Elsevier Science B.V. All rights reserved.