Cookies help us deliver our services. By using our services, you agree to our use of cookies. More information

Neufer 2014 Abstract MiP2014

From Bioblast
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
Assessing ATP production and oxygen consumption simultaneously in permeabilized fibers: ATP/O.

Link:

Neufer DP

Mitochondr Physiol Network 19.13 - MiP2014

Lark DS, Ryan TE, Anderson EJ, Neufer PD (2014)

Event: MiP2014

The biochemical efficiency of oxidative phosphorylation (OXPHOS), quantified as the amount of ATP produced per oxygen atom consumed (ATP/O or ~P/O), is vital to maintaining proper myocyte energetics. However, despite its central importance, it is difficult to experimentally determine the ~P/O ratio as a function of metabolic demand, and therefore, the relationship between OXPHOS efficiency and metabolic demand is poorly understood. O2 consumption (high-resolution respirometry) and ATP production (determined fluorometrically using a 2-deoxyglucose – hexokinase – glucose-6-phosphate dehydrogenase – NADP+ respiratory clamp system [1]), rates were measured simultaneously in permeabilized mouse oxidative and glycolytic skeletal muscle fiber bundles using a customized Oroboros Oxygraph-2k.


With pyruvate+malate (5+2 mM) as substrate, at low [ADP] (5-20 Β΅M), the ~P/O ratio increased as a function of [ADP], independent of an increase in O2 consumption. Maximal ~P/O peaked at ~2.0 and was not different between oxidative and glycolytic muscle. Pharmacological inhibition of adenylate kinase decreased ATP production rate but did not alter ADP-dependent increases in OXPHOS efficiency.

These findings suggest that mitochondria respond to low levels of metabolic demand by initially increasing OXPHOS efficiency.


β€’ O2k-Network Lab: US NC Greenville Neufer PD, US NC Greenville Anderson EJ


Labels: MiParea: Respiration 


Organism: Mouse  Tissue;cell: Skeletal muscle  Preparation: Permeabilized tissue 

Regulation: ADP, ATP production, Coupling efficiency;uncoupling  Coupling state: OXPHOS 

HRR: Oxygraph-2k  Event: A4, Oral  MiP2014 

Affiliation

1-East Carolina Diabetes Obesity Inst; 2-Dep Kinesiolog; 3-Dep Physiol; 4-Dep Pharmacolog Toxicolog; East Carolina Univ, Greenville, NC, USA. – [email protected]

References and acknowledgements

Supported by: National Institute of Health R01 DK096907 (USA).

  1. Gouspillou G, Rouland R, Calmettes G, Deschodt-Arsac V, Franconi J-M, Bourdel-Marchasson I, Diolez P (2011) Accurate determination of the oxidative phosphorylation affinity for ADP in isolated mitochondria. PloS One 6:e20709.