Devaux 2023 J Comp Physiol B

Devaux JBL, Hedges CP, Birch N, Herbert N, Renshaw GMC, Hickey AJR (2023) Electron transfer and ROS production in brain mitochondria of intertidal and subtidal triplefin fish (Tripterygiidae). https://doi.org/10.1007/s00360-023-01495-4

» J Comp Physiol B 193:413-24. PMID: 37145369 Open Access »

Devaux Jules BL, Hedges Chris P, Birch Nigel, Herbert Neill, Renshaw Gillian MC, Hickey Anthony JR (2023) J Comp Physiol B

Abstract: While oxygen is essential for oxidative phosphorylation, O₂ can form reactive species (ROS) when interacting with electrons of mitochondrial electron transport system. ROS is dependent on O₂ pressure (PO₂) and has traditionally been assessed in O₂ saturated media, PO₂ at which mitochondria do not typically function in vivo. Mitochondrial ROS can be significantly elevated by the respiratory complex II substrate succinate, which can accumulate within hypoxic tissues, and this is exacerbated further with reoxygenation. Intertidal species are repetitively exposed to extreme O₂ fluctuations, and have likely evolved strategies to avoid excess ROS production. We evaluated mitochondrial electron leakage and ROS production in permeabilized brain of intertidal and subtidal triplefin fish species from hyperoxia to anoxia, and assessed the effect of anoxia reoxygenation and the influence of increasing succinate concentrations. At typical intracellular PO₂, net ROS production was similar among all species; however at elevated PO₂, brain tissues of the intertidal triplefin fish released less ROS than subtidal species. In addition, following in vitro anoxia reoxygenation, electron transfer mediated by succinate titration was better directed to respiration, and not to ROS production for intertidal species. Overall, these data indicate that intertidal triplefin fish species better manage electrons within the ETS, from hypoxic-hyperoxic transitions. • Keywords: Hypoxia, Hypoxia tolerance, Reactive oxygen species, Respirometry, Succinate • Bioblast editor: Plangger M • O2k-Network Lab: NZ Auckland Hickey AJ

Labels: MiParea: Respiration 

Stress:Oxidative stress;RONS  Organism: Fishes  Tissue;cell: Nervous system  Preparation: Permeabilized cells 

Coupling state: LEAK, OXPHOS, ET  Pathway: N, S, CIV, NS  HRR: Oxygraph-2k, O2k-Fluorometer 

2023-05, AmR, O2k-brief