Activity of digestive hydrolases in carp Cyprinus carpio with different mercury content in food

Enzymatic Activity in the Gastrointestinal Tract of Pimelodus maculatus (Teleostei, Siluriformes) in Two Neotropical Reservoirs with Different Trophic Conditions

“…The intestinal enzymatic activity is probably adapted to digest a wide source of foods, mainly those of animal origin; therefore, feeding habits for this species is probably highly dependent on the presence of peptidase enzymes (Lundstedt et al 2004;Xiong et al 2011). Studies conducted in artificially polluted environments lead to more conclusive results, such as those reported by Kuz'mina et al (2013) who showed that Cyprinus carpio (Linnaeus, 1758) individuals submitted to mercury-enriched food showed an increase in the activity of intestinal peptidases and a corresponding decrease in the activity of intestinal glycosidase. Nevertheless, studies performed with fishes collected from their natural environment are more realistic, even if the chosen enzymatic activity is not a clear biomarker, data showing spatial variations and comparison of enzymatic profile among species are relevant to the freshwater ecology and important for further investigations.…”

“…In this study, gastrointestinal and hepatic activities for trypsinlike and chymotrypsin-like peptidases and for β-glucosidase were relatively with low variation among the specimens. This was relevant, since the biochemical parameters such as enzymatic activities were usually affected by the pollutants ( Van der Oost et al 2003;Pathiratne et al 2009;Kuz'mina et al 2013). Thus, before specific comparisons between the two reservoirs, one must point out that these hydrolases are promising biomarker for future studies given the acceptable low intraspecific variations and the easy assaying of their activities with chromogenic or natural substrates.…”

“…Different environmental conditions may affect the activity of digestive enzymes in fishes and comparison of biochemical parameters between the individuals from different environments can be useful to furnish the biomarkers of pollution and other ecological parameters. Measurements of variation in the enzymatic activity and specificity are widely used to assess the environmental quality and some enzymes are particularly important such as carbonic anhydrase and hydrolases (Kuz'mina et al 1996(Kuz'mina et al , 2003(Kuz'mina et al , 2013Lionetto et al 2012;Filippov et al 2013), apart from cytochrome P450 that is directly involved in the transformation of xenobiotics (Uno et al 2012). A Siluriformes fish species widely distributed in the rivers and reservoirs of Southeastern Brazil was chosen for this study.…”