In isolated mammalian myocardium, oxygen consumption increased significantly as muscle length increased, largely due to lengthening itself rather than tension maintenance.
How do variations in muscle length and rate influence oxygen consumption in isolated mammalian myocardium?
Muscle length and rate are primary determinants of oxygen consumption in isolated mammalian myocardium, providing physiological context for Starling's law of the heart.
Oxygen consumption and resting and developed tension in isolated strips of mammalian myocardium were simultaneously measured in specially constructed chambers. In a resting preparation the O 2 consumption increased significantly as the length of the muscle was increased. The evidence suggests that the augmented Qo 2 (µl/mg dry wt/hr.) is largely a result of the lengthening, per se, and is not due to the maintenance of tension. In the beating preparation, variations in rate and length accounted for most of the change in the O 2 uptake, tension being a less significant factor. The possible relationship of these findings to ‘Starling's law of the heart’ is discussed.
William J. Whalen (Wed,) conducted a other in Isolated mammalian myocardium. Muscle lengthening and rate variations vs. Shorter muscle length / resting state was evaluated on Oxygen consumption (Qo2). In isolated mammalian myocardium, oxygen consumption increased significantly as muscle length increased, largely due to lengthening itself rather than tension maintenance.