Comparison of the effect of a mitochondrial uncoupler, 2,4‐dinitrophenol and adrenaline on oxygen radical production in the isolated perfused rat liver

Abstract

Using the isolated perfused rat liver, we examined the effect of stimulation of mitochondrial respiration by 2,4-dinitrophenol (2,4-DNP) and adrenaline on reactive oxygen species (ROS) production, liver damage and lipid peroxidation. ROS production was monitored by luminol- and lucigenin-enhanced chemiluminescence and oxygen uptake was measured simultaneously. Liver damage and lipid peroxidation were evaluated by measuring hepatic lactate dehydrogenase (LDH) and thiobarbituric acid reacting substances (TBARS) release. Tissue ROS level decreased and oxygen uptake increased soon after 2,4-DNP infusion. On termination of 2,4-DNP infusion, there was a sharp increase in lucigenin-enhanced chemiluminescence, which declined slowly, but luminol-enhanced chemiluminescence did not change prominently. Hepatic LDH and TBARS release increased gradually during 2,4-DNP infusion and were manifested by termination of the infusion. Allopurinol did not affect ROS production and TBARS release, but delayed increases in LDH release after termination of 2,4-DNP infusion. Adrenaline, which stimulates mitochondrial respiration without uncoupling caused similar but smaller ROS changes observed in 2,4-DNP. LDH and TBARS release were not affected significantly by adrenaline infusion. These results indicate that uncoupling of oxidative phosphorylation decreases ROS production and restoration of oxidative phosphorylation enhances ROS production and liver damage. Xanthine oxidase is unlikely to contribute to enhanced ROS production after termination of 2,4-DNP but has some protective effect during uncoupling.

Alteration of mitochondrial efficiency affects oxidative balance, development and growth in frog (Rana temporaria) tadpoles

“…Hence, an increased proton flux across the inner membrane via the F 0 F 1 -ATP synthase (state 3 respiration) or other proton leak pathways such as uncoupling proteins or mitochondrial uncouplers, including the protonophore 2,4-dNP, would attenuate ROS production by lowering the membrane potential (Korshunov et al, 1997;Brand, 2005;Rey et al, 2010). The decreased ROS generation found in 2,4-dNP-treated tadpoles is thus in accordance with previously reported data in isolated mitochondria, organs or whole animals (Okuda et al, 1992;Batandier et al, 2006;da Silva et al, 2008). Interestingly, chronically treated tadpoles exhibited a better oxidative status, i.e.…”

Mitochondrial depolarization underlies delay in permeability transition by preconditioning with isoflurane: roles of ROS and Ca2+

“…It is possible that these differences are a result of variations in the approach to measure ⌬⌿ m and ROS and/or the different nature of action and potency of DNP and FCCP, because it was shown that another uncoupling agent exhibited concentration-dependent, dual effect on mitochondrial ROS production (36). Consistent with our results, several groups have demonstrated attenuation of ROS production by DNP (40,41).…”

Hepatitis C Virus Core Protein Inhibits Mitochondrial Electron Transport and Increases Reactive Oxygen Species (ROS) Production

“…These data indicate that complex I is the primary source of the increased ROS production in HCV transgenic mitochondria. The uncoupler FCCP reduced ROS under all conditions as previous reported (39,40); however, the transgenic mitochondria retained increased complex I ROS production (Fig. 8C).…”