Related Experiment Video
Updated: Aug 15, 2026

Respirometric Oxidative Phosphorylation Assessment in Saponin-permeabilized Cardiac Fibers
Published on: February 28, 2011
Response time of mitochondrial oxygen consumption following stepwise changes in cardiac energy demand
1Laboratory for Physiology, Free University, Amsterdam, The Netherlands.
Abstract:
We determined the speed with which mitochondrial oxygen consumption and therefore the mitochondrial ATP-synthesis adapted to changes in metabolic demand in the rabbit heart. This was done by measuring the oxygen uptake of the whole heart during a stepwise change in heart rate and correcting for the time taken by diffusion and by convective transport in the blood vessels. Data for the correction for transport time were obtained from the response of venous oxygen concentration to a stepwise change of arterial oxygen concentration. The time constant of the response of mitochondrial oxygen consumption to a step change in heart rate was found to be 4-8 s.
Related Concept Videos
Energy Supply for Muscle Contraction
Pathophysiology of Cardiac Performance

