Difference between revisions of "Cook 2013 J Exp Biol"
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|injuries=Hypoxia | |injuries=Hypoxia | ||
|organism=Fish | |organism=Fish | ||
|tissues= | |tissues=Heart, Skeletal muscle | ||
|preparations=Permeabilized tissue | |preparations=Permeabilized tissue | ||
|topics=Aerobic and Anaerobic Metabolism | |topics=Aerobic and Anaerobic Metabolism | ||
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Revision as of 11:23, 27 February 2013
| Cook DG, Iftikar FI, Baker DW, Hickey AJ, Herbert NA (2013) Low-O2 acclimation shifts the hypoxia avoidance behaviour of snapper (Pagrus auratus) with only subtle changes in aerobic and anaerobic function. J Exp Biol 216: 369-378. |
Cook DG, Iftikar FI, Baker DW, Hickey AJ, Herbert NA (2013) J Exp Biol
Abstract: It was hypothesised that chronic hypoxia acclimation (preconditioning) would alter the behavioural low-O2 avoidance strategy of fish as a result of both aerobic and anaerobic physiological adaptations. Avoidance and physiological responses of juvenile snapper (Pagrus auratus) were therefore investigated following a 6 week period of moderate hypoxia exposure (10.2–12.1 kPa PO2, 21±1°C) and compared with those of normoxic controls (PO2=20–21 kPa, 21±1°C). The critical oxygen pressure (Pcrit) limit of both groups was unchanged at ~7 kPa, as were standard, routine and maximum metabolic rates. However, hypoxia-acclimated fish showed increased tolerances to hypoxia in behavioural choice chambers by avoiding lower PO2 levels (3.3±0.7 vs 5.3±1.1 kPa) without displaying greater perturbations of lactate or glucose. This behavioural change was associated with unexpected physiological adjustments. For example, a decrease in blood O2 carrying capacity was observed after hypoxia acclimation. Also unexpected was an increase in whole-blood P50 following acclimation to low-O2, perhaps facilitating Hb–O2 off-loading to tissues. In addition, cardiac mitochondria measured in situ using permeabilised fibres showed improved O2 uptake efficiencies. The proportion of the anaerobic enzyme lactate dehydrogenase, at least relative to the aerobic marker enzyme citrate synthase, also increased in heart and skeletal red muscle, indicating enhanced anaerobic potential, or in situ lactate metabolism, in these tissues. Overall, these data suggest that a prioritization of O2 delivery and O2 utilisation over O2 uptake during long-term hypoxia may convey a significant survival benefit to snapper in terms of behavioural low-O2 tolerance. • Keywords: Hypoxia acclimation, Lactate
• O2k-Network Lab: NZ Auckland Hickey AJ
Labels:
Stress:Hypoxia Organism: Fish"Fish" is not in the list (Human, Pig, Mouse, Rat, Guinea pig, Bovines, Horse, Dog, Rabbit, Cat, ...) of allowed values for the "Mammal and model" property. Tissue;cell: Heart, Skeletal muscle Preparation: Permeabilized tissue
Regulation: Aerobic and Anaerobic Metabolism"Aerobic and Anaerobic Metabolism" is not in the list (Aerobic glycolysis, ADP, ATP, ATP production, AMP, Calcium, Coupling efficiency;uncoupling, Cyt c, Flux control, Inhibitor, ...) of allowed values for the "Respiration and regulation" property.
HRR: Oxygraph-2k
