Mercury tissue residue approach in Chironomus riparius: Involvement of toxicokinetics and comparison of subcellular fractionation methods

Role of cellular compartmentalization in the trophic transfer of mercury species in a freshwater plant-crustacean food chain

“…components [23]. This latter kind of detoxification strategy probably also could explain the absence of excretion in G. fossarum in our exposure condition [38].…”

“…The variation of concentrations in gammarids with time can be modelled by a toxicokinetic one-compartment equation, allowing uptake and excretion rates to be estimated [23]. Our data highlighted the absence of significant excretion over the 7-day-long exposure period considered (data not shown), hence a simplified linear model to describe accumulation kinetics over time was used (Eq.…”

Enzymatic validation of species‐specific protocols for metal subcellular fractionation in freshwater animals

“…Conversely, our results on Chironomus riparius tend to indicate that for some organisms with fragile tissues such as Diptera larvae and most likely many other insect larvae, homogenizations that could be considered relatively weak (e.g., trimmed with a surgical razor blade, 2 s of grinding with an Elvehjem‐Potter pestle) lead to enzymatic results very close to our selection criteria in terms of homogenization efficiency (Table ). Hence, a bias in metal content in the debris fraction for Diptera larvae studies (Bechard et al ; Rosabal et al ; Gimbert et al ) seems highly unlikely even though most of these studies have not optimized their homogenization methods to their fractionated species. Our results suggest as well that this tissue's fragility can be linked with the sample storage at −80°C prior to fractionation and that the fractionation of fresh Diptera larvae may call for a stronger homogenization; to our knowledge no studies have examined this point as they all used frozen samples.…”

“…Also, the possible transfer of metals from HDP to HSP during the heat treatment of the cytosol was pointed out by some authors (Bragigand and Berthet ; Geffard et al ). To verify this possible transfer, metal distribution results between HDP and HSP following the usual heat treatment can be compared with metal distribution results between cytosolic compounds with a size exclusion chromatography method (Gimbert et al ).…”

Chromium bioavailability in aquatic systems impacted by tannery wastewaters. Part 2: New insights from laboratory and in situ testing with Chironomus riparius Meigen (Diptera, Chironomidae)

“…Knowledge of the subcellular fate of metals is therefore required to better understand the physiological processes underlying their bioaccumulation and toxicity. Such methods have been developed for larvae of chironomids (Gimbert et al, 2016;Péry et al, 2008) and will have to be considered to further clarify the metabolically available concentration of Cr that can affect the development of chironomids at different stages in real-field situations.…”