Sub-cellular partitioning of Cd, Cu and Zn in tissues of indigenous unionid bivalves living along a metal exposure gradient and links to metal-induced effects

Subcellular partitioning profiles and metallothionein levels in indigenous clams Moerella iridescens from a metal-impacted coastal bay

“…This can be explained by the fact that, like most aquatic organisms, M. iridescens can efficiently, at least to a certain extent, regulate uptake and/or excretion of essential metals through homeostatic mechanisms over a wide range of ambient exposure levels, while for the non-essential metals, there appeared to be no, or only a weak, mechanism to regulate or limit uptake or excretion (Voets et al, 2009) tial trace metals with some form of homeostatic control. In this respect, our results are completely in accordance with the findings of other researchers (Bervoets et al, 2004;Bonneris et al, 2005), who also reported that bioaccumulated Cd concentrations were more responsive to the spatial gradients than were those of bioaccumulated Zn, even though the ambient [M] max /[M] min ratios in exposure conditions were less for Cd than for Zn. In a biomonitoring context, M. iridescens would thus be more responsive to the external Cd and Pb exposure gradients than to the Cu and Zn exposure gradients.…”

Impact of mercury on the activity pattern of a marker enzyme in a freshwater bivalve

“…In nature, metals are bound differently in the gill and in the digestive gland of the mussels and metal detoxification in the former organ may be less effective than the latter (Bonneris et al 2005). The intermittent high and low enzyme activity observed in both the tissues in mussels exposed to the different concentrations of metals shall also be attributed to valve closure, often reported in mussels exposed to higher concentration of metals (Tran et al 2003).…”

“…Difference in antioxidant profile and oxyradical metabolism for tissues with digestive or respiratory functions have been indicated in invertebrates and fishes (Regoli et al 2002). Also, in nature, metals are bound differently in the gills and in the digestive gland of mussels and that metal detoxification in the former organ may be less effective than in the latter (Bonneris et al 2005).…”

Subcellular distribution of Cd and Zn and MT mRNA expression in the hepatopancreas of Sinopotamon henanense after single and co-exposure to Cd and Zn

“…Additionally, six subcellular components were obtained through differential centrifugation, NaOH digestion and heat denaturation steps including: metal sensitive fraction [MSF-mitochondria (Mit), microsome and lysosome (Mic & Lys) and heat-denaturable proteins (HDP)], detoxified metals [BDM-heat-stable proteins (HSP) and metal-rich granules (MRG)] and cellular debris & nuclei. It has been discovered that HSP was very important in biological detoxification according to some previous studies (Bonneris et al, 2005;Goto and Wallace, 2007;Rosabal et al, 2012), and metallothionein (MT) has been found to play an important role in the storage of metals (Wallace et al, 2003;Goto and Wallace, 2007). MT, a low-molecular-weight, cysteine-rich protein with no aromatic amino acids and high metalbinding affinity, is identified in a wide variety of animals (Klaassen et al, 1999).…”