Pike Liver Research Articles

Iron-binding biomolecules in the soluble hepatic fraction of the northern pike (Esox lucius): two-dimensional chromatographic separation with mass spectrometry detection.

Iron plays vital roles in important biological processes in fish, but can be toxic in high concentrations. The information on metalloproteins that participate in maintenance of Fe homeostasis in an esocid fish, the northern pike, as an important freshwater bioindicator species, are rather scarce. The aim of this study was to identify main cytosolic constituents that sequester Fe in the northern pike liver. The method applied consisted of two-dimensional HPLC separation of Fe-binding biomolecules, based on anion-exchange followed by size-exclusion fractionation. Apparent molecular masses of two main Fe-metalloproteins isolated by this procedure were ~360 kDa and ~50 kDa, with the former having more acidic pI, and indicated presence of ferritin and hemoglobin, respectively. MALDI-TOF-MS provided confirmation of ferritin subunit with a m/z peak at 20.65 kDa, and hemoglobin with spectra containing main m/z peak at 16.1 kDa, and smaller peaks at 32.1, 48.2, and 7.95 kDa (single-charged Hb-monomer, dimer, and trimer, and double-charged monomer, respectively). LC-MS/MS with subsequent MASCOT database search confirmed the presence of Hb-β subunits and pointed to close relation between esocid and salmonid fishes. Further efforts should be directed towards optimization of the conditions for metalloprotein analysis by mass spectrometry, to extend the knowledge on intracellular metal-handling mechanisms.

Methylmercury in northern pike (Esox lucius) liver and hepatic mitochondria is linked to lipid peroxidation

Methylmercury (MeHg) readily bioaccumulates and biomagnifies in aquatic food webs leading to elevated concentrations in fish and may thus induce toxicity. Oxidative stress is a suggested effect of MeHg bioaccumulation in fish. However, studies on how MeHg triggers oxidative stress in wild fish are scarce. The purpose of this study was to link the subcellular distribution of MeHg in the liver of northern pike from the St. Maurice River (Québec, Canada), affected by two run-of-river (RoR) dams, artificial wetlands, forest fires, and logging activity, to lipid peroxidation as an indicator of oxidative stress. We also evaluated the protective effects of the glutathione (GSH) system and selenium (Se), as they are known to alleviate MeHg toxicity. A customized subcellular partitioning protocol was used to separate the liver into metal-sensitive (mitochondria, microsome/lysosome and HDP – heat-denatured proteins) and metal-detoxified fractions (metal-rich granules and HSP – heat-stable proteins). We examined the relation among THg, MeHg, and Se concentration in livers and subcellular fractions, and the hepatic ratio of total GSH (GSHt) to oxidized glutathione (GSSG) on lipid peroxidation levels, using the concentrations of malondialdehyde (MDA), a product of lipid peroxidation. Results showed that hepatic MDA concentration was positively correlated with the combined MeHg and Se concentrations in northern pike liver (r2 = 0.88, p < 0.001) and that MDA concentrations were best predicted by MeHg associated with the mitochondria (r2 = 0.71, p < 0.001). This highlights the need for additional research on the MeHg influence on fish health and the interactions between Hg and Se in northern pike.

Modifications of Thermal-Induced Northern Pike (Esox lucius) Liver Ferritin on Structural and Self-Assembly Properties.

Ferritin, as an iron storage protein, regulates iron metabolism and delivers bioactive substances. It has been regarded as a safe, new type of natural iron supplement, with high bioavailability. In this paper, we extracted and purified ferritin from northern pike liver (NPLF). The aggregation stabilities, assemble properties, and structural changes in NPLF were investigated using electrophoresis, dynamic light scattering (DLS), circular dichroism (CD), UV–Visible absorption spectroscopy, fluorescence spectroscopy, and transmission electron microscopy (TEM) under various thermal treatments. The solubility, iron concentration, and monodispersity of NPLF all decreased as the temperature increased, and macromolecular aggregates developed. At 60 °C and 70 °C, the α-helix content of ferritin was greater. The content of α-helix were reduced to 8.10% and 1.90% at 90 °C and 100 °C, respectively, indicating the protein structure became loose and lost its self-assembly ability. Furthermore, when treated below 80 °C, NPLF maintained a complete cage-like shape, according to the microstructure. Partially unfolded structures reassembled into tiny aggregates at 80 °C. These findings suggest that mild thermal treatment (80 °C) might inhibit ferritin aggregation while leaving its self-assembly capacity unaffected. Thus, this study provides a theoretical basis for the processing and use of NPLF.

Environmental exposure of northern pike to a primary wastewater effluent: Impact on the lipidomic profile and lipid metabolism

Lipids play important roles in growth, reproduction, locomotion, and migration of fish. Municipal effluents, which are complex mixtures of biological and chemical compounds including flame retardants, have been shown to alter lipid metabolism in environmentally and experimentally exposed fish. Down-regulation of several genes coding for fatty acid metabolism enzymes has previously been reported in male northern pike (Esox lucius) collected in the St. Lawrence River (QC, Canada) downstream of a major primary wastewater treatment plant (WWTP) point of discharge. The main objective of this study was to investigate the effects of exposure to the Montreal’s WWTP effluent on the lipidomic profile (i.e., fatty acids, acylcarnitines, and phospholipids) as well as the transcription of genes related to lipid metabolism in the liver of northern pike collected upstream and downstream of this WWTP effluent. Halogenated flame retardant concentrations were also determined in pike liver and used as markers of exposure to this effluent. Greater concentrations of saturated and monounsaturated lysophosphatidylcholines (LPCs) and lower concentrations of polyunsaturated LPCs were determined in the liver of pike collected downstream of the WWTP compared to those collected upstream. Lower mRNA levels of peroxisome proliferator-activated receptor alpha (pparα), a major regulator of lipid metabolism, were also measured in pike exposed to Montreal’s WWTP effluent. In addition, the relative contributions (%) of LPC 18:2 and LPC14:0, compounds used as markers of obesity and inflammation, were significantly correlated with halogenated flame retardant concentrations and fish girth. Results of the present study suggest that chronic environmental exposure to a primary WWTP effluent can modulate the transcription of genes related to lipid metabolism, and hence affect the hepatic phospholipid composition of pike from the St. Lawrence River.

Accumulation of Silver in Yellow Perch ( Perca flavescens) and Northern Pike ( Esox lucius) From a Lake Dosed with Nanosilver.

A total of 15 kg of silver nanoparticles (AgNPs) was added continuously over two ice-free field seasons to a boreal lake (i.e., Lake 222) at the IISD Experimental Lakes Area in Canada. We monitored the accumulation of silver (Ag) in the tissues of yellow perch ( Perca flavescens) and northern pike ( Esox lucius) exposed to the AgNPs under environmentally relevant conditions. The greatest accumulation was observed in the liver tissues of pike, and a single pike sampled in the second year of additions had the highest concentration observed in liver of 5.1 micrograms per gram of wet weight. However, the Ag concentrations in gill and muscle tissue of both pike and perch did not exceed 0.35 micrograms per gram of wet weight. Following additions of AgNP, the Ag residues in fish tissues declined, with a half-life of Ag in pike liver of 119 days. Monitoring using passive sampling devices and single-particle inductively coupled plasma mass spectrometry during the AgNP addition phase confirmed that Ag nanoparticles were present in the water column and that estimated mean concentrations of Ag increased over time to a maximum of 11.5 μg/L. These data indicate that both a forage fish and a piscivorous fish accumulated Ag in a natural lake ecosystem dosed with AgNPs, leading to Ag concentrations in some tissues of the piscivorous species that were 3 orders of magnitude greater than the concentrations in the water.

Pike (Esox lucius) Bio-indicator of Heavy Metal Pollution in Anzali Wetland

The economical and industrial aspects of aquatic organisms like fish make the topic of toxicants important. The present study was carried out to measure the accumulation of heavy metals (Pb, Sn and Zn) in the liver and muscle of pike (Esox lucius). Totally, 60 pikes have been collected from 6 stations in the Anzali wetland (the south coast of the Caspian Sea) included Pirbazar, Anzali, Abkenar, Sangachin, Beshman, and Khazarvila. Tissue samples were prepared according to MOOPAM method. Zn concentration was determined using a atomic absorption spectrophotometer. Pb and Sn were also measured by graphite furnace atomic absorption spectrophotometer. The highest concentrations of heavy metals were measured in the muscle and liver of pikes collected from Anzali and Pirbazar stations (located in the northeast of the wetland) due to the large amount of heavy metals release into these stations from adjacent shipbuilding factories and oil jetty. Comparison of the levels of three metals in fish tissues with international standards showed that Pb concentration was significantly higher in Anzali and Pirbazar fish than the permissible limit determined by WHO.

Purification and properties of glutathione S-transferase from the pike liver

Purification and properties of glutathione S-transferase from the pike liver

Ultrastructural features of Glisson's capsule and the overlying mesothelium in rat, monkey and pike liver

Samples from the liver of a male rat (Sprague–Dawley), a monkey ( Macacus rhesus), and a longnose gar pike ( Lepisosteus osseus) were studied in a transmission electron microscope to provide cytological and histological information about structures previously poorly documented in the literature. Glisson's capsule consisted of dense, irregular connective tissue of typical Type-I collagen fibrils. The capsule was formed by a single stratum of fibroblasts in the rat and in the pike, but by one or two strata of fibroblasts in the monkey. In the rat, but not in the monkey or pike, fibroblast processes interdigitated with processes from the hepatocytes. In the pike, fibroblast processes extended toward both mesothelium and hepatocytes. In some areas of the rat and pike, mesothelial cells had desmosomal connections and microvillous projections into the peritoneal cavity. Marginated heterochromatin was more abundant in the rat and monkey. The mesothelium was discontinuous in the rat and monkey but, in areas of discontinuity, the capsular surface was covered by a basal lamina, often barely perceptible beneath mesothelial cells of the rat and monkey, but prominent in the pike. In the pike, the mesothelium had numerous pinocytotic vesicles on both peritoneal and capsular surfaces.

Decreasing lead levels in Swedish biota revealed by 36 years (1969–2004) of environmental monitoring

Since the 1980s, lead levels decreased significantly in most marine biota from the Baltic Sea, the Kattegatt and the Skagerrack and in terrestrial biota from south and central Sweden, analysed in the National Swedish Environmental Monitoring Programme. In herring and cod liver, the decrease was 4.2-7.1% annually 1981-2003 and in perch liver and guillemot eggs analysed since the middle of the 1990s the decrease was 10-13%. In kidneys of young starlings from south and central Sweden, lead levels decreased 6.2-12% annually and the annual decrease in liver and kidney from young moose was 8.8% and 6.5%, respectively. In northern Sweden, lead levels decreased in pike liver by 2.8% between 1969 and 1994 and in reindeer liver by 3.5% annually while a significant increase (5% annually 1981-1994) has been detected in arctic char. In some marine biota, there were indications of a larger decrease during the last ten years compared to the whole period. The large decline in lead emission to the atmosphere during the last twenty years, mainly because of decreasing use of leaded gasoline has obviously resulted in decreasing lead levels in biota.

Effect of Toxic Factors on Intracellular Proteinase Activity In Freshwater Fish

Kaivarainen, E. I., N. N. Nemova, M. Y. Krupnova, L. A. Bondareva: The Effect of Toxic Factors on Intracellular Proteinase Activity in Freshwater Fish. Acta vet. Bmo 67, 1998: 306-316. The effect of ore-dressing sewage on intracellular proteinase activity was studied in the larvae of European whitefish and rainbow trout and in some types of freshwater fish (pike, roach, and perch) tissue (gills, liver, kidney, spleen, and muscles) in aquarium experiments and in contaminated and clean water bodies. Cathepsin 0 (lysosome proteinase) activity was observed to increase 1.5-2.0 times in the larvae of rainbow trout present in undiluted sewage and at 5-fold dilution in the aquarium experiment, as compared with the control. This effect increased 7 times in the larvae of European whitefish at S-fold dilution, as compared with the control. Similar changes were reported for the tissues of pike and roach caught in a contaminated zone. Cathepsin 0 activity increased 3 and 6 times in the gills and liver of pike, as compared with the control. Cathepsin B (lysosome proteinase) activity decreased about 1.5 times in the larvae of rainbow trout kept in aquaria with undiluted ore-dressing sewage and subjected S-fold dilution. In addition, Ca2+-activated proteinases (neutral cytosol proteinases) were found to be less active in the muscles of pike and roach studied affected by ore-dressing sewage in a contaminated zone, so that calpain I activity declined 1.5-2.0 times, and calpain II activity decreases two times or was not detected at all. Similar effects were reported for the perch muscle caught in the aquarium experiment with undiluted sewage. The above results show that some parameters of intracellular proteolysis can be used as a biochemical test in biomonitoring of water bodies. Cathepsins, caipains, ore-dressing selVage, biotesting The impact of human activities on water bodies has substantially increased in the past few years.Therefore, more attention is now given to the existence and survival of aquatic organisms in contaminated water (Alabaster and Lloyd 1984; Evtushenko et al. 1985; L u ky ane n ko 1983). Fish are extremely sensitive to toxins that can inhibit metabolic pathways and reduce the resistance of cells in their organism (Evtushenko et al. 1985; B ardac hand Li fe 1982), It should be noted in this connection that most types of industrial sewage contain at least two toxicants. It is difficult, therefore, to assess their toxic effect on fish and other organisms. The effect of toxicants on the organism is accompanied by the invol vement of the cellular and molecular mechanisms that control metabolic homeostasis. The degree of toxicity is related to the efficiency of protective and restoring mechanisms in the tissue analysed, such as a system of intracellular proteolysis with lysosomal and nonlysosomal pathways. Proteinases can inactivate, transform, and excrete chemical compounds. Proteinase activity is an important parameter of biotesting because biochemical changes in the cells and tissues

Heavy metal speciation and its biological consequences in a group of lakes polluted by a smelter, Flin Flon, Manitoba, Canada

Abstract Comparative study of lakes polluted with Cd, Zn and Cu from a smelter at Flin Flon, Canada showed that the availability of heavy metals to sedimentary micro-organisms and aquatic food-chain organisms depends on the abundance of DTPA-extractable (bio-available) metal species in the sediments rather than total metal concentrations. Microbial methylation of Hg and resulting accumulation of Hg by northern pike muscle are inhibited by DTPA-extractable Cd but are not significantly affected by total Cd. Similarly, the Cd content of water, plankton and pike liver, and the toxic effects of Cd on heterotrophic sedimentary microbes, are more strongly dependent on DTPA-extractable Cd than on total Cd concentrations in the sediments. The extractability of sediment-bound Cd with DTPA is enhanced by organic matter but is depressed if sulfide exceeds a critical concentration. The DTPA-extractable Cd fraction may include lipophilic complexes that accumulate in fish tissues over time, as suggested by an increasingly significant positive correlation between liver Cd and fork length in pike with increasing abundance of DTPA-extractable Cd. Although Cd is less abundant than Zn or Cu in the DTPA-extractable metal pool, it has the strongest toxic effect on microbial activity, the relative toxicity increasing in the order Zn Among white sucker, concentrations of Hg in muscle tissue and Cd in liver tissue are not significantly dependent on DTPA-extractable Cd but are depressed by sedimentary sulfides and Fe oxyhydroxides, respectively. The contrast between the results for pike and sucker suggests differences in metal uptake pathways and kinds of metal species assimilated, reflecting the difference in the feeding habits of the two fish species.

Elucidation of cDNA sequences for metallothioneins from rainbow trout, stone loach and pike liver using the polymerase chain reaction

Metallothionein cDNAs were generated from the livers of three fish species and amplified by PCR. Two distinct coding sequences (A and B) were elucidated for rainbow trout metallothioneins but single isoforms were encoded by genes isolated from the stone loach and pike. Different sized transcripts were observed both with stone loach and pike but these were accounted for by altered lengths of 3' untranslated regions.

The hepatic glutathione content and glutathione S-transferase activity in the pike ( Esox lucius L.) and rat

1. 1. The content of glutathione and glutathione disulfide and the activity of the glutathione S-transferase were determined in the liver of pike and rat. 2. 2. It was found that the liver of pike contains far less glutathione than the liver of rats, while the glutathione disulfide content was similar in both species. 3. 3. The activity of the hepatic glutathione S-transferase was more effective in pike than in rats.

A comparative toxicological study on pike ( Esox lucius L.) from the river Rhine and river Lahn

The influence of environmental pollutants on morphological and hepatic biochemical parameters of mature pike from the river Rhine and river Lahn was investigated. Liver content of aromatic organohalogen compounds in Rhine pike was up to 40 times higher than found in pike from the river Lahn. Lead and mercury residues in Rhine pike liver tissue were about twice as high as in Lahn pike. Copper and zinc contents were comparatively higher in Lahn pike. Cadmium occurred in about equal concentration in both groups. Interrelations between body weight and age, between body length and age, between body weight and body length and between liver weight and body weight in both pike groups revealed no influence by xenobiotics. Distribution pattern of hepatic porphyrins in the Rhine pike differed significantly from that in the Lahn pike. The in vitro activity of the hepatic uroporphyrinogen decarboxylase of pike from the river Rhine was markedly lower than in pike from the river Lahn.

Preparation and characterization of subcellular fractions from the intestinal mucosa of the Northern pike (Esox lucius), with special emphasis on enzymes involved in xenobiotic metabolism

Abstract The present study was designed to prepare and characterize subcellular fractions from the intestinal mucosa of the Northern pike (Esox lucius), with special emphasis on the preparation of a microsomal fraction suitable for studying xenobiotic metabolism. The purity of the different fractions obtained by differential centrifugation, as well as the recovery of different organelles, was determined using both enzyme markers and morphological examination with the electron microscope. The subcellular distributions of several enzymes involved in drug metabolism (NADPH-cytochrome c reductase, NADH-ferricyanide reductase, epoxide hydrolase activity towards both cis- and trans-stilbene oxide as substrates, and glutathione transferase) were also examined. The subcellular distributions obtained here for drug-metabolizing and marker enzymes closely resembled those reported for rat and pike liver. The microsomal fraction obtained contained about 50% of the total endoplasmic reticulum. This fraction was relatively free of nuclei, mitochondria, Golgi, peroxisomes and cytosol, but relatively heavily contaminated with lysosomes and fragments of the plasma membrane. Within the limitations discussed, the subfractions prepared here are suitable for further characterization of drug-metabolizing systems in the intestinal mucosa of the Northern pike, as well as for other studies with this tissue.

Preparation and characterization of subcellular fractions suitable for studies of drug metabolism from the trunk kidney of the northern pike ( Esox lucius) and assay of certain enzymes of xenobiotic metabolism in these subfractions

The present study was designed to prepare and characterize subcellular fractions from the trunk kidney of the Northern pike ( Esox lucius), with special emphasis on the preparation of a microsomal fraction suitable for studying xenobiotic metabolism. The purity of the different fractions obtained by differential centrifugation, as well as the recovery of different organelles, was determined using both enzyme markers and morphological examination with the electron microscope. Finally, the subcellular distributions of several drug-metabolizing enzymes (NADPH-cytochrome c reductase, NADH-ferricyanide reductase, glutathione transferase, epoxide hydrolase) were determined. With the exception of NADPH-cytochrome c reductase, the subcellular distributions obtained here for drug metabolizing and marker enzymes closely resembled those reported for rat liver. NADPH-cytochrome c reductase was apparently partially solubilized here from microsomal vesicles by an endogenous protease, which reduced its usefulness as a marker enzyme and raises questions concerning the measurement of activities catalyzed by the cytochrome P-450 system in these subfractions. In other respects the microsomes and supernatant fraction prepared here from the trunk kidney of the pike seem to be as well suited for investigations of drug metabolism as are the corresponding fractions from rat and pike liver.

Accumulation, metabolism and tissue distribution of the mothproofing agent eulan WA New in the Northern Pike Esox lucius

After a 4h dosing period with the mothproofing agent Eulan WA New in surrounding water, most pike tissues showed a high ratio of PADs (polychloro-2-aminodiphenyl ethers; minor components of Eulan WA (New) to PCSDs (polychloro-2-[ chloromethyl-sulphonamido] diphenyl ethers; the major component and active ingredient of Eulan WA New). Particularly high PADs to PCSDs ratios were shown throughout the dosing periods in pike liver. In a second experiment, over a shorter time course and employing purified pentachloro-2-(chloromethylsulphonamido) diphenyl ether (6-PCSD), the liver was identified as a primary site of PAD formation. Very high concentrations of PCSDs and PADs were found in the bile and also appear to accumulate in the spleen and kidney.

Preparation and characterization of subcellular fractions from the liver of the northern pike, Esox lucius

The present study was designed to prepare and characterize subcellular fractions from the liver of the Northern pike ( Esox lucius), with special emphasis on the preparation of microsomal fractions suitable for studying xenobiotic metabolism. The purity of the different fractions obtained by differential centrifugation, as well as the recovery of different organelles, was determined using both enzyme markers and morphological examination with the electron microscope. Attempts were also made to increase the recovery of fragments of the endoplasmic reticulum in the microsomal fraction. Finally, the subcellular distribution of several drug-metabolizing enzymes (cytochrome P-450, benzpyrene monooxygenase, epoxide hydrolase and glutathione transferases) were determined. With the exception of the subcellular distribution of epoxide hydrolase, the results obtained here resemble closely those reported for rat liver and the microsomal fraction prepared is highly suitable for further studies of drug metabolism in pike liver.

DEHP in the vicinity of an industrial area in Finland

Samples of fish, net plankton, freshwater and soil arthropods and soil obtained in the vicinity of an industrial area were analysed for di-(2-ethyl hexyl) phthalate (DEHP) content. The highest concentration was found in soil arthropods (2·8 mg/kg). No contamination was discovered in plankton, but the levels of contamination in other organisms were as follows: 0·1 mg/kg in small fish (fry and sticklebacks), freshwater arthropods, molluscs and perch ( Perca fluviatilis); 0·5 mg/kg in bream ( Abramis brama) and 1·1 mg/kg in roach ( Rutilus rutilus). The muscle and kidney of pike ( Esox lucius) were free from contamination but the contamination of pike's liver was equivalent to 2·3 mg/kg.