Cadiz 2019 Comp Biochem Physiol B Biochem Mol Biol
|Cadiz L, Bundgaard A, Malte H, Fago A (2019) Hypoxia enhances blood O2 affinity and depresses skeletal muscle O2 consumption in zebrafish (Danio rerio). Comp Biochem Physiol B Biochem Mol Biol 234:18-25.|
Abstract: Zebrafish (Danio rerio) are widely used animal models. Nevertheless, the mechanisms underlying hypoxia tolerance in this species have remained poorly understood. In the present study, we have determined the effects of hypoxia on blood-O2 transport properties and mitochondrial respiration rate in permeabilized muscle fibres of adult zebrafish exposed to either 1) a gradual decrease in O2 levels until fish lost equilibrium (~1 h, acute hypoxia), or 2) severe hypoxia (PO2 ∼ 15 Torr) for 48 h (prolonged hypoxia). Acute, short-term hypoxia caused an increase in hemoglobin (Hb) O2 affinity (decrease in P50), due to a decrease in erythrocyte ATP after erythrocyte swelling. No changes in iso-Hb expression patterns were observed between hypoxic and normoxic treatments. Prolonged hypoxia elicited additional reponses on O2 consumption: lactate accumulated in the blood, indicating that zebrafish relied on glycolysis for ATP production, and mitochondrial respiration of skeletal muscle was overall significantly inhibited. In addition, male zebrafish had higher hypoxia tolerance (measured as time to loss of equilibrium) than females. The present study contributes to our understanding of the adaptive mechanisms that allow zebrafish, and by inference other fish species, to cope with low O2 levels.
Copyright © 2019 Elsevier Inc. All rights reserved.
• Bioblast editor: Plangger M
Labels: MiParea: Respiration
Stress:Hypoxia Organism: Zebrafish Tissue;cell: Skeletal muscle Preparation: Permeabilized tissue
Regulation: Oxygen kinetics Coupling state: LEAK, OXPHOS, ET Pathway: N, NS HRR: Oxygraph-2k