RESUMO
Enrofloxacin is widely used for the prevention and control of bacterial diseases in aquaculture. The liver is crucial for enrofloxacin metabolism, but enrofloxacin can induce liver damage. Herein, we explored proteomic changes in the liver of grass carp (Ctenopharyngodon idellus) following treatment with enrofloxacin using isobaric tag for relative and absolute quantitation (iTRAQ) technology. All experiments included two biological replicates and blank controls. Among the 3082 proteins identified, 103 were differentially abundant, comprising 49 up- and 54 downregulated proteins. Gene Ontology (GO) annotation identified macromolecular complex (63.60%), intracellular non-membrane-bound organelle (51.50%), and non-membrane-bound organelle (51.50%) as the most enriched cellular component terms. Structural molecule activity (26.80%), structural constituent of ribosome (17.90%), and calcium ion binding (16.10%) were the top three molecular function terms. Organic substance biosynthetic process (37.80%), biosynthetic process (37.80%), and protein metabolic process (37.80%) were the top three biological process terms. The Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis found 17 enriched KEGG pathways, with protein digestion and absorption, extracellular matrix (ECM)-receptor interactions, and ribosome and focal adhesion the most significant (p < 0.001). Analysis of the most enriched pathways revealed that chymotrypsin-like precursor, pancreatic elastase precursor, Na+/K+ transporting ATPase, collagen, and dermatopontin were upregulated, while ribosomal proteins, alpha-actinin, and myosin light chain were downregulated. These findings suggest that enrofloxacin affects liver function and has a risk of inducing an inflammatory response in extrahepatic organs.