Last Word on Viewpoint: What is the relationship between the acute muscle protein synthetic response and changes in muscle mass?

摘要

to the editor: We would like to thank all of the eminent scientists who provided commentaries (see Ref. 1) on our recent Viewpoint article (4). Several important points were brought up in the commentaries that warrant further comment. The technical challenge of measuring both muscle protein synthesis (MPS) and breakdown simultaneously in the same individual is a major limitation that precludes us from making statements about the effects of exercise and nutritional manipulations on net balance of myonbrillar proteins. However, we are highly confident that acute measures of MPS and changes in this variable (not muscle protein breakdown) are the primary influential factor affecting tissue remodelling and that measurement of only MPS does not mean we lack essential information as a measure of muscle anabolism. Support for our position, as reflected in our Viewpoint article, can be seen in the situations where MPS aligns with the relative long-term anabolic effect of different exercise and nutritional manipulations.