Hickey 2012 J Comp Physiol B: Difference between revisions
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*[[O2k-Fluorescence LED2-Module]] | *[[O2k-Fluorescence LED2-Module]] | ||
== Correction == | |||
An OROBOROS Oxygraph-2k was used in this publication, whereas the Anton Paar/OROBOROS Oxygraph was the first-generation instrument for high-resolution respirometry, which was replaced by the Oxygraph-2k in 2002. | |||
* ''Further details'': [[Gnaiger 2012 Abstract Bioblast-Gentle Science]] |
Revision as of 13:50, 30 March 2015
Hickey AJ, Renshaw GM, Speers-Roesch B, Richards JG, Wang Y, Farrell AP, Brauner CJ (2012) A radical approach to beating hypoxia: depressed free radical release from heart fibres of the hypoxia-tolerant epaulette shark (Hemiscyllum ocellatum). J Comp Physiol B 182:91-100. |
Hickey AJ, Renshaw GM, Speers-Roesch B, Richards JG, Wang Y, Farrell AP, Brauner CJ (2012) J Comp Physiol B
Abstract: Hypoxia and warm ischemia are primary concerns in ischemic heart disease and transplant and trauma. Hypoxia impacts tissue ATP supply and can induce mitochondrial dysfunction that elevates reactive species release. The epaulette shark, Hemiscyllum ocellatum, is remarkably tolerant of severe hypoxia at temperatures up to 34 ยฐC, and therefore provides a valuable model to study warm hypoxia tolerance. Mitochondrial function was tested in saponin permeabilised ventricle fibres using high-resolution respirometry coupled with purpose-built fluorospectrometers. Ventricular mitochondrial function, stability and reactive species production of the epaulette shark was compared with that of the hypoxia-sensitive shovelnose ray, Aptychotrema rostrata. Fibres were prepared from each species acclimated to normoxic water conditions, or following a 2 h, acute hypoxic exposure at levels representing 40% of each species' critical oxygen tension. Although mitochondrial respiratory fluxes for normoxia-acclimated animals were similar for both species, reactive species production in the epaulette shark was approximately half that of the shovelnose ray under normoxic conditions, even when normalised to tissue oxidative phosphorylation flux. The hypoxia-sensitive shovelnose ray halved oxidative phosphorylation flux and cytochrome c oxidase flux was depressed by 34% following hypoxic stress. In contrast, oxidative phosphorylation flux of the epaulette shark ventricular fibres isolated from acute hypoxia exposed the animals remained similar to those from normoxia-acclimated animals. However, uncoupling of respiration revealed depressed electron transport systems in both species following hypoxia exposure. Overall, the epaulette shark ventricular mitochondria showed greater oxidative phosphorylation stability and lower reactive species outputs with hypoxic exposure, and this may protect cardiac bioenergetic function in hypoxic tropical waters. โข Keywords: Mitochondria, Hypoxia tolerance, Shark
โข O2k-Network Lab: NZ Auckland Hickey AJ, CA Vancouver Richards JG
Labels: MiParea: Respiration, Comparative MiP;environmental MiP
Stress:Hypoxia, Ischemia-reperfusion;preservation"Ischemia-reperfusion;preservation" is not in the list (Cell death, Cryopreservation, Ischemia-reperfusion, Permeability transition, Oxidative stress;RONS, Temperature, Hypoxia, Mitochondrial disease) of allowed values for the "Stress" property., Oxidative stress;RONS
Tissue;cell: Heart Preparation: Permeabilized tissue
Coupling state: OXPHOS
HRR: Oxygraph-2k, O2k-Fluorometer
Product information
Correction
An OROBOROS Oxygraph-2k was used in this publication, whereas the Anton Paar/OROBOROS Oxygraph was the first-generation instrument for high-resolution respirometry, which was replaced by the Oxygraph-2k in 2002.
- Further details: Gnaiger 2012 Abstract Bioblast-Gentle Science