Plasma protein changes in horse after prolonged physical exercise: A proteomic study ☆ Fausto Scoppetta a, 1 , Micaela Tartaglia a, 1 , Giovanni Renzone b , Luca Avellini a , Alberto Gaiti a , Andrea Scaloni b, ⁎ , Elisabetta Chiaradia a, ⁎ a Biochemistry Laboratory, Sport Horse Research Centre, Department of Pathologic, Diagnostic and Clinical Veterinary Medicine, University of Perugia, 06126 Perugia, Italy b Proteomics and Mass Spectrometry Laboratory, ISPAAM, National Research Council, 80147 Naples, Italy ARTICLE INFO ABSTRACT Available online 24 April 2012 Physical exercise induces various stress responses and metabolic adaptations that have not yet been completely elucidated. Novel biomarkers are needed in sport veterinary medicine to monitor training levels and to detect subclinical conditions that can develop into exercise- related diseases. In this study, protein modifications in horse plasma induced by prolonged, aerobic physical exercise were investigated by using a proteomic approach based on 2-DE and combined mass spectrometry procedures. Thirty-eight protein spots, associated with expres- sion products of 13 genes, showed significant quantitative changes; spots identified as membrane Cu amine oxidase, α-1 antitrypsin, α-1 antitrypsin-related protein, caeruloplasmin, α-2 macroglobulin and complement factor C4 were augmented in relative abundance after the race, while haptoglobin β chain, apolipoprotein A-I, transthyretin, retinol binding protein 4, fibrinogen γ chain, complement factor B and albumin fragments were reduced. These results indicate that prolonged physical exercise affects plasma proteins involved in pathways related to inflammation, coagulation, immune modulation, oxidant/antioxidant activity and cellular and vascular damage, with consequent effects on whole horse metabolism. This article is part of a Special Issue entitled: Farm animal proteomics. © 2012 Elsevier B.V. All rights reserved. Keywords: Horse Endurance Plasma proteins Physical exercise Proteomics 1. Introduction Depending on the intensity, duration and type of physical exercise, equine metabolism has to adapt to nervous, cardio- vascular, endocrine and respiratory system requirements. Metabolic variations include changes in catabolic reactions to maintain optimal ATP concentration and high O 2 consumption, enhanced substrate depletion and heat dissipation, as well as augmented biochemical processes to face the accumulation of resulting metabolites [1–5]. Similarly to other stressors, it needs adequate responses to re-establish homeostatic equilibrium; this is mainly achieved by the hormonal system [5,6]. Circulat- ing hormone concentrations change as result of variations in glandular production/secretion, metabolic clearance rate, tar- get tissue uptake, molecular degradation and regulation of carrier proteins [5,7]. The stress response is initiated in the hypothalamic– pituitary–adrenal axis with sympathetic nervous system acti- vation, followed by production of adrenaline and glucocorti- coids that increase cellular ATP production and promote gluconeogenesis. During the response to physical exercise, adrenaline and glucocorticoids also modulate the immune JOURNAL OF PROTEOMICS 75 (2012) 4494 – 4504 ☆ This article is part of a Special Issue entitled: Farm animal proteomics. ⁎ Corresponding authors. E-mail addresses: andrea.scaloni@ispaam.cnr.it (A. Scaloni), elisabetta.chiaradia@unipg.it (E. Chiaradia). 1 These authors contributed equally to this work. 1874-3919/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.jprot.2012.04.014 Available online at www.sciencedirect.com www.elsevier.com/locate/jprot