Galli 2023 Comp Biochem Physiol A Mol Integr Physiol
| Galli GLJ, Shiels HA, White E, Couturier CS, Stecyk JAW (2023) The air-breathing Alaska blackfish (Dallia pectoralis) suppresses brain mitochondrial reactive oxygen species to survive cold hypoxic winters. https://doi.org/10.1016/j.cbpa.2022.111355 |
» Comp Biochem Physiol A Mol Integr Physiol 276:111355. PMID: 36529208
Galli Gina LJ, Shiels Holly A, White Ed, Couturier Christine S, Stecyk Jonathan AW (2023) Comp Biochem Physiol A Mol Integr Physiol
Abstract: The Alaska blackfish (Dallia pectoralis) is the only air-breathing fish in the Arctic. In the summer, a modified esophagus allows the fish to extract oxygen from the air, but this behavior is not possible in the winter because of ice and snow cover. The lack of oxygen (hypoxia) and near freezing temperatures in winter is expected to severely compromise metabolism, and yet remarkably, overwintering Alaska blackfish remain active. To maintain energy balance in the brain and limit the accumulation of reactive oxygen species (ROS), we hypothesized that cold hypoxic conditions would trigger brain mitochondrial remodeling in the Alaska blackfish. To address this hypothesis, fish were acclimated to warm (15 °C) normoxia, cold (5 °C) normoxia or cold hypoxia (5 °C, 2.1-4.2 kPa; no air access) for 5-8 weeks. Mitochondrial respiration, ADP affinity and H202 production were measured at 10 °C in isolated brain homogenates with an Oroboros respirometer. Cold acclimation and chronic hypoxia had no effects on mitochondrial aerobic capacity or ADP affinity. However, cold acclimation in normoxia led to a suppression of brain mitochondrial H202 production, which persisted and became more pronounced in the cold hypoxic fish. Overall, our study suggests cold acclimation supresses ROS production in Alaska blackfish, which may protect the fish from oxidative stress when oxygen becomes limited during winter. • Keywords: Brain, Cold, Fish, Hypoxia, Mitochondria, Temperature • Bioblast editor: Plangger M • O2k-Network Lab: UK Manchester Galli GL
Labels: MiParea: Respiration
Stress:Oxidative stress;RONS, Hypoxia Organism: Fishes Tissue;cell: Nervous system Preparation: Homogenate
Regulation: Temperature
HRR: Oxygraph-2k
2023-03
