Targeted proteomics for the indirect detection of dexamethasone treatment in bovines.

The illegal use of pharmacologically active compounds for growth promotion in food-producing species poses risks for consumer health and animal welfare. Surveillance relies on the quantification of drug residues in animal fluids or tissues, but the efficacy can be negatively affected due to undetectable residual concentrations in biological matrices. Consequently, techniques focusing on the indirect biological effects of exogenous compound administration have been proposed as more sensitive detection methods. The purpose of the present study is to develop a tandem mass spectrometry analytical method based on low-energy collision-induced dissociation (CID-MS/MS) using multiple reaction monitoring (MRM) for the quantification of 12 potential protein markers of skeletal muscle to detect anabolic treatments with dexamethasone. Protein markers identified in a previous study applying a 2D-DIGE proteomics approach have been quantified using the signature peptide method. A group of proteins were confirmed as reliable markers. Quantitative results enabled a predictive model to be defined based on logistic regression for the detection of treated animals. The developed model was finally cross-validated in an independent animal set. Graphical abstract Analytical workflow used for the quantification of indirect protein markers of dexamethasone treatment.