Boushel 2013 Abstract MiP2013

Boushel RC (2013) Convective O2 delivery, diffusion and mitochondrial OXPHOS components of VO2 during exercise in health and disease. Mitochondr Physiol Network 18.08.

Link:

Boushel RC (2013)

Event: MiP2013

Maximal oxygen consumption (V_O2) in the organism is defined by the integrated functional capacities of multiple organ systems and characterized by proportionate design of the structural components of the O2 cascade from lung to mitochondria across a wide range of species. Yet, humans exhibit an excess capacity of muscle mitochondrial OXPHOS capacity relative to convective O2 delivery. This pattern holds with aging and in chronic diseases such as chronic obstructive lung disease and type 2 diabetes despite a lower expression and/or dysfunction of mitochondria. Muscle diffusional O₂ conductance (D_O2) is largely dependent on the capillary volume:muscle interface which influences the mean transit time of erythrocytes and off-loading of O2 from haemoglobin at a given p50 and blood flow. Convective O₂ delivery remains a dominant factor defining maximal V_O2 as revealed by comparison of muscle D_O2, mean capillary p_O2, and V_O2 during exercise engaging small to large muscle groups. The increase in muscle VO2 with endurance training in young, healthy humans is characterized by proportional increases in O₂ convection and diffusion, with variable enhancement of mitochondrial OXPHOS capacity, which remains in excess to maximize the p_O2 gradient from the red blood cell to cytochrome c oxidase.

• O2k-Network Lab: DK Copenhagen Boushel RC

Labels: MiParea: Respiration, mt-Biogenesis;mt-density, Exercise physiology;nutrition;life style 

Organism: Human 

Coupling state: OXPHOS 

HRR: Oxygraph-2k 

Exercise 

Affiliations and author contributions

1 - Heart and Circulatory Section, Dept of Biomedical Sciences, University of Copenhagen; Department of Anaesthesia, Bispebjerg Hospital, Denmark.

Email: boushel@sund.ku.dk