Hypoxic acclimation improves mitochondrial bioenergetic function in large yellow croaker Larimichthys crocea under Cu stress

• Published in: Ecotoxicology and environmental safety Vol. 224; p. 112688
• Main Authors: Zeng, Lin, Li, Wen-Cheng, Zhang, Hui, Cao, Ping, Ai, Chun-Xiang, Hu, Bing, Song, Wei
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.11.2021; Elsevier
• Subjects: Cu exposure; Hypoxic acclimation; Mitochondria; Oxidative phosphorylation; Hypoxic acclimation; Cu exposure; Mitochondria; Oxidative phosphorylation
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2021.112688

The purpose of this study was to investigate how pre-hypoxia exposure affected the mitochondrial structure and bioenergetic function of large yellow croaker in responding to Cu stress. Fish were acclimated to normoxia and 3.0 mg DO L−1 for 48 h, then subjected to 0 and 120 μg Cu L−1 for another 48 h. Hypoxic acclimation did not affect mitochondrial ultrastructure and reactive oxygen species (ROS), but reduced oxidative phosphorylation (OXPHOS) efficiency. Cu exposure impaired mitochondrial ultrastructure, increased ROS generation and inhibited OXPHOS efficiency. Compared with Cu exposure alone, hypoxic acclimation plus Cu exposure reduced ROS production and improved OXPHOS efficiency by enhancing mitochondrial respiratory control ratio, mitochondrial membrane potential, and activities and gene expressions of electron transport chain enzymes. In conclusion, hypoxic acclimation improved the mitochondrial energy metabolism of large yellow croaker under Cu stress, facilitating our understanding of the molecular mechanisms regarding adaptive responses of hypoxia-acclimated fish under Cu stress. [Display omitted] •Pre-hypoxia did not affect ROS generation, but reduced OXPHOS efficiency.•Cu impaired mitochondrial ultrastructure and bioenergetic function.•Pre-hypoxia had an antagonistic effect on Cu-induced oxidative damage.•Pre-hypoxia improved mitochondrial energy metabolism in fish under Cu stress.