Analysis of intracellular distribution of selected metals/metalloid in the liver of brown trout (Salmo trutta Linnaeus, 1758) from the Krka River

Dragun, Zrinka; Matoničkin Kepčija, Renata; Kolar, Nicol (2017) Analysis of intracellular distribution of selected metals/metalloid in the liver of brown trout (Salmo trutta Linnaeus, 1758) from the Krka River. Other. UNSPECIFIED. (Unpublished)

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Abstract

Intracellular distribution of nine metals/metalloid was studied in liver of brown trout (Salmo trutta Linnaeus, 1758) from the Krka River, sampled in October 2015 at two sites, the Krka River spring as a reference site, and the Krka River downstream from the town Knin, as a contaminated site. Slight concentration increase of several metals in dissolved form in the river water has confirmed anthropogenic influence on the Krka River downstream from the town Knin. The aim of this study was to determine distribution of nine selected elements between soluble (cytosolic) and insoluble hepatic fraction, which was accomplished by hepatic tissue homogenization and subsequent centrifugation and determination of total and cytosolic metal/metalloid concentrations in the liver. The results of this study have shown the highest percentage partition of Cd in soluble hepatic fraction (>80%), whereas the partition of Co, Se, Zn, Cu and Mn in the cytosol was less pronounced (50-80%). Metals Tl, Fe and Mo were highly present in the insoluble hepatic fraction. The presence in the insoluble hepatic fraction of all essential elements, except Zn, increase with increase of their accumulation in the liver, probably as a sign of their detoxification. Opposite scenario was observed for nonessential elements Cd and Tl. Their percentage in cytosol increased following the increase of their accumulation in the liver. The second aim of this study was to describe distribution of metals/metalloid among cytosolic biomolecules of different molecular masses, which was accomplished by chromatographic separation of hepatic cytosols using principle of size exclusion, and subsequent measurement of metal/metalloid concentrations in obtained fractions which contained biomolecules of different molecular masses by use of HR ICP-MS. Some of the most interesting results of this study which could be pointed out were: elution of Cu, Cd and Zn with biomolecules of molecular masses corresponding to metallothioneins; increase of Fe peak at elution time of ferritin, protein which is involved in Fe storage, as a response to accumulation increase of Fe in the liver; elution of Co, Mo, Mn and Zn in broad range of molecular masses, which corresponds well with their role as cofactors to numerous enzymes; elution of Se with the biomolecules of molecular masses lower than 5 kDa, which can be associated to known selenocompounds, selenonein and selenomethionin, which are involved in organism defence from oxidative stress; and elution of nonessential and extremly toxic metal Tl with biomolecules of molecular masses from 60 to 300 kDa, which also include molecular masses of several enzymes in which activation Tl is involved, like aldehyde dehydrogenase and (Na++K+)-ATP-ase. The presented results are the first step towards the identification of proteins and other biomolecules which are involved in metabolism and detoxification of metals and metalloids in trout liver and which make potential biomarkers of metal exposure and effects.

Item Type:

Report (Other)

Uncontrolled Keywords:

brown trout (Salmo trutta Linnaeus, 1758); the Krka River; metals; metalloid; cytosolic biomolecules; HPLC, ICP-MS

Subjects:

NATURAL SCIENCES > Chemistry
NATURAL SCIENCES > Biology
NATURAL SCIENCES > Interdisciplinary Natural Sciences > Environmental Science

Divisions:

Division for Marine and Enviromental Research

Projects: