Near infrared spectroscopy: in situ studies of skeletal and cardiac muscle.

Abstract

Assessment of muscle oxygenation during work is an area of considerable research interest owing to questions about the variables regulating the cellular uptake of oxygen (O2). Cardiac and red skeletal muscles can vary the level of O2 uptake by 20-fold at steady state in response to sustained work (1). Maximal O2 uptake has been proposed to be regulated by a number of variables including the flow of O2,and turnover of NADH, ADP and inorganic phosphate (Pi). A specific rate-limiting step, however, has never been identified experimentally. High rates of oxygen utilization in myoglobin containing muscle are achieved at relatively low sarcoplasmic oxygen tensions. Estimates of muscle PO2 based upon measurements of myoglobin saturation at near maximal steady state work indicate values in the 2–3 ton range, i.e. myoglobin is about half saturated with oxygen (2).KeywordsLiver MitochondrionNear Infrared SpectroscopyGracilis MuscleMuscle OxygenationConsiderable Research InterestThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.