A nuclear magnetic resonance (NMR) based metabolomic study was conducted to investigate the metabolism of
an anesthetic agent in rainbow trout, Oncorhynchus mykiss. Fish were anesthetized with 150 mg/L clove oil and
compared to a control group of non-exposed fish. Blood sampling were collected after complete anesthesia was
achieved and samples subject to 1HNMR spectroscopy. A partial least squares discriminant analysis (PLS-DA) of
plasma metabolome content showed a clear pattern of metabolites involved in anesthesia induced with clove oil
and the non-exposed control fish. The plasma levels of valine, isoleucine, creatine, N,N-dimethylglycine and
glucose significantly increased in the anesthetized group compared to the control group according to metabolite
profiling results. In contrast, the plasma levels of N-acetylglucosamine and succinate significantly decreased in
the anesthetized fish compared to the control group. Pathway analysis of the metabolites identified in our study
showed that the anesthetic mainly affects the biochemical pathways related to energy and amino acid metabolism.
These include valine, leucine and isoleucine biosynthesis, tryptophan metabolism, histidine metabolism,
amino sugar and nucleotide sugar metabolism, glycine, serine and threonine metabolism, arginine and proline
metabolism, starch and sucrose metabolism, citrate cycle, galactose metabolism, glyoxylate and dicarboxylate
metabolism and glycerophospholipid metabolism.