Metabolic responses of clams, Ruditapes decussatus and Ruditapes philippinarum, to short-term exposure to lead and zinc

This study investigated the effects of 48 h heavy metal exposure upon the metabolic profiles of Ruditapes decussatus and Ruditapes philippinarum using H-1 NMR metabolomics. Both species were exposed to increasing concentrations of lead nitrate (10, 40, 60 and 100 mu g/L) and zinc chloride (20, 50,100 and 150 mu g/L), under laboratory conditions. ICP-OES analysis was further performed on the clams' samples in order to verify the occurrence of heavy metal bioaccumulation. With respect to the controls, the metabolic profiles of treated R. decussatus exhibited higher levels of organic osmolytes and lower contents of free amino acids. An opposite behavior was shown by R. philippinarum. In terms of heavy metal, the exposure effects were more evident in the case of Pb rather than Zn. These findings show that NMR-based metabolomics has the required sensitivity and specificity for the identification of metabolites that can act as sensitive indicators of contaminant-induced stress. (C) 2016 Elsevier Ltd. All rights reserved.