Cook 2013 J Exp Biol: Difference between revisions
No edit summary |
Beno Marija (talk | contribs) No edit summary ย |
||
(6 intermediate revisions by 3 users not shown) | |||
Line 1: | Line 1: | ||
{{Publication | {{Publication | ||
|title=Cook DG, Iftikar FI, Baker DW, Hickey AJ, Herbert NA (2013) Low-O<sub>2</sub> acclimation shifts the hypoxia avoidance behaviour of snapper (''Pagrus auratus'') with only subtle changes in aerobic and anaerobic function. J Exp Biol 216: 369- | |title=Cook DG, Iftikar FI, Baker DW, Hickey AJ, Herbert NA (2013) Low-O<sub>2</sub> acclimation shifts the hypoxia avoidance behaviour of snapper (''Pagrus auratus'') with only subtle changes in aerobic and anaerobic function. J Exp Biol 216:369-78. | ||
|info=[http://www.ncbi.nlm.nih.gov/pubmed/23038727 PMID: 23038727] | |info=[http://www.ncbi.nlm.nih.gov/pubmed/23038727 PMID: 23038727 Open Access] | ||
|authors=Cook DG, Iftikar FI, Baker DW, Hickey AJ, Herbert NA | |authors=Cook DG, Iftikar FI, Baker DW, Hickey AJ, Herbert NA | ||
|year=2013 | |year=2013 | ||
|journal=J Exp Biol | |journal=J Exp Biol | ||
|abstract=It was hypothesised that chronic hypoxia acclimation (preconditioning) would alter the behavioural low-O<sub>2</sub> 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 (10.2โ12.1 kPa P<sub>O<sub>2</sub></sub>, 21ยฑ1ยฐC) and compared with those of normoxic controls (P<sub>O<sub>2</sub></sub>=20โ21 kPa, 21ยฑ1ยฐC). The critical oxygen pressure (P<sub>crit</sub>) 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 P<sub>O<sub>2</sub></sub> levels (3.3ยฑ0.7 vs 5.3ยฑ1.1 kPa) without displaying greater perturbations of lactate or glucose. This behavioural change was associated with unexpected physiological adjustments. For example, a decrease in blood O<sub>2</sub> carrying capacity was observed after hypoxia acclimation. Also unexpected was an increase in whole-blood P<sub>50</sub> following acclimation to low-O<sub>2</sub>, perhaps facilitating HbโO<sub>2</sub> off-loading to tissues. In addition, cardiac mitochondria measured ''in situ'' using permeabilised fibres showed improved O<sub>2</sub> 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 O<sub>2</sub> delivery and O<sub>2</sub> utilisation over O<sub>2</sub> uptake during long-term hypoxia may convey a significant survival benefit to snapper in terms of behavioural low-O<sub>2</sub> tolerance. | |abstract=It was hypothesised that chronic hypoxia acclimation (preconditioning) would alter the behavioural low-O<sub>2</sub> 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 (10.2โ12.1 kPa P<sub>O<sub>2</sub></sub>, 21ยฑ1ยฐC) and compared with those of normoxic controls (P<sub>O<sub>2</sub></sub>=20โ21 kPa, 21ยฑ1ยฐC). The critical oxygen pressure (P<sub>crit</sub>) 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 P<sub>O<sub>2</sub></sub> levels (3.3ยฑ0.7 vs 5.3ยฑ1.1 kPa) without displaying greater perturbations of lactate or glucose. This behavioural change was associated with unexpected physiological adjustments. For example, a decrease in blood O<sub>2</sub> carrying capacity was observed after hypoxia acclimation. Also unexpected was an increase in whole-blood P<sub>50</sub> following acclimation to low-O<sub>2</sub>, perhaps facilitating HbโO<sub>2</sub> off-loading to tissues. In addition, cardiac mitochondria measured ''in situ'' using permeabilised fibres showed improved O<sub>2</sub> 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 O<sub>2</sub> delivery and O<sub>2</sub> utilisation over O<sub>2</sub> uptake during long-term hypoxia may convey a significant survival benefit to snapper in terms of behavioural low-O<sub>2</sub> tolerance. | ||
|keywords=Hypoxia acclimation, Lactate | |keywords=Hypoxia acclimation, Lactate, Preconditioning, Sparidae, Oxygen affinity, Metabolism, Swimming, Activity, Haemoglobin, Mitochondria, Respiration | ||
|mipnetlab=NZ Auckland Hickey AJ | |mipnetlab=NZ Auckland Hickey AJ | ||
}} | }} | ||
{{Labeling | {{Labeling | ||
| | |area=Respiration, Comparative MiP;environmental MiP | ||
|injuries=Ischemia-reperfusion | |||
|organism=Fishes | |||
|tissues=Heart, Skeletal muscle | |tissues=Heart, Skeletal muscle | ||
|preparations=Permeabilized tissue | |preparations=Permeabilized tissue | ||
|instruments=Oxygraph-2k | |instruments=Oxygraph-2k | ||
}} | }} |
Latest revision as of 17:46, 8 November 2016
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 216:369-78. |
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 (10.2โ12.1 kPa PO2, 21ยฑ1ยฐC) and compared with those of normoxic controls (PO2=20โ21 kPa, 21ยฑ1ยฐC). 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 (3.3ยฑ0.7 vs 5.3ยฑ1.1 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 HbโO2 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. โข Keywords: Hypoxia acclimation, Lactate, Preconditioning, Sparidae, Oxygen affinity, Metabolism, Swimming, Activity, Haemoglobin, Mitochondria, Respiration
โข O2k-Network Lab: NZ Auckland Hickey AJ
Labels: MiParea: Respiration, Comparative MiP;environmental MiP
Stress:Ischemia-reperfusion Organism: Fishes Tissue;cell: Heart, Skeletal muscle Preparation: Permeabilized tissue
HRR: Oxygraph-2k