Updated project metadata. In the present work, we evaluated the effects of membrane-initiated cortisol actions in vivo in the proteome of rainbow trout (Oncorhynchus mykiss) skeletal muscle. Quantitative iTRAQ analyses were performed to examine proteomic changes in rainbow trout stimulated with physiological concentrations of cortisol and cortisol-BSA. A total of 873 proteins were identified, among which 38 proteins were commonly and differentially expressed under both conditions. Functional clustering analysis revealed an upregulation of proteins associated with mitochondria, metal-binding and secreted proteins.