Rainbow Trout Salmo Research Articles

A Phylogenetic Comparison Between Acute Monocytic Leukemia Cells and Monocytes–Macrophages in Lower Vertebrates

In humans, monocytes and macrophages (MØ) play a central role in immune regulation, tissue maintenance and pathogen control. In lower vertebrates, a few studies have been conducted on MØ like cells. In acute monocytic leukemia monocytic cells, as immature cells restrained in one of the phases of their ontogenesis, would offer the opportunity to rebuild an archaic condition helpful to understand the phylogenesis. Therefore, aim of this work was to characterize in the Rainbow trout (Salmo Gairdneri Richardson) MØ and compare them with acute leukemia monocytic cells.In the trout, MØ's morphology is similar to that of mammals. In particular, MØ possess an irregular embryoshaped nucleus occupying 2/3 of the cell, while the peripheral cytoplasmic profile is irregular with extroflexed plasmalemma and pseudopods.A morphological transition towards MØ is featured by a wavy hyaline classical membrane and an irregular and extroflexed surface.Some aspects of erythrophagocytosis represented a finding of great interest indicating that the hemocatheretic function could take place directly in circulation. This condition, also observed in human acute monocytic leukemia, suggests that the information to the erythrophagocytosis is restrained under physiological conditions.Non-specific esterases, which are positive in human MØ smear and MØ from human lymph node tissue, were also positive in the teleost studied but with a dysomogeneous pattern. Consequently non-specific esterase system is phylogenetically conserved.A lack of immune-reactivity with the anti-CD68 monoclonal antibody (MoAb) on smear and trout tissue sections was observed. On the contrary, strong positivity was detected on human lymph node sections.In trout, the presence of MØ and circulating MØ like cells exhibiting an erythrocatheretic function in the circulation would indicate a primordial function that has later been replaced by the liver and the spleen.

FISH IMMUNOLOGY. I. BINDING AND ENGULFMENT OF CANDIDA ALBICANS BY ERYTHROCYTES OF RAINBOW TROUT (SALMO GAIRDNERI RICHARDSON)

ABSTRACTThe role of fish erythrocytes (FE) as phagocytic cells has poorly been investigated, until now. Here, we have focussed our attention on the interplay between rainbow trout (Salmo gairdneri Richardson) erythrocytes and Candida albicans (CA). At the same time, the intervention of autologous head kidney macrophages (MØ) in the CA processing by FE has been studied. Data show that CA particles bind to FE, which, in turn, are able to engulf but not kill them. In the presence of MØ, a decrease of FE with bound CA occurs and, in some microscopic images, FE form rosettes with MØ. Phagocytosis of CA is higher in rosetting MØ than in non-rosetting ones. According to our findings, it appears that FE represent a reservoir of engulfed CA and rosetting is an efficacious phenomenon of presentation of pathogens to MØ, where an effective clearance of them can take place.

Sonoelectroanalytical Determination of Heavy Metals in Fish Gill Mucous

Fish gill mucous is used as a nondestructive biomarker for the detection of heavy metals by sono-square-wave anodic stripping voltammetry (sono-SWASV). The mucous sample was obtained by gently rinsing the rainbow trout (Salmo gairdneri) with a solution of borate buffer at pH 7. A glassy carbon electrode plated in situ with mercury was used in a face on arrangement with the ultrasonic horn to first demonstrate that voltammetric measurements can accurately be made in borate buffer. The optimum deposition potential and ultrasound power for copper from a dilute mucous solution was then determined and used to give a quantitative assessment of copper content using the microaddition technique. The results had a % RSD of less than 2 % and compared favorably with an independent blind analysis. The potential of the technique for detection of other heavy metals for example lead, was also demonstrated. We conclude that sono-SWASV of gill mucous may present a novel alternative to the destructive conventional techniques due to its accuracy, rapidity and facile methodology.

ACTIVITY OF ESTERASES FROM DIFFERENT TISSUES OF FRESHWATER FISH AND RESPONSES OF THEIR ISOENZYMES TO INHIBITORS

Activity of nonspecific esterase from different tissues (i.e., liver, gallbladder, heart, intestine, and muscle) of five species of freshwater fish, namely, topmouth gudgeon (Pseudorasbora parva), goldfish (Carassius auratus), nile tilapia (Tilapia nilotica), mosquitofish (Gambusia affinis), and rainbow trout (Salmo gairdneri) was tested using α-naphthyl acetate as sub strate. The results indicated that activity of the enzyme was mainly concentrated in the digestive system (i.e., intestine, liver, bile). The overall activity was highest in nile tilapia, followed by mosquitofish, topmouth gudgeon, goldfish, and lowest in rainbow trout. Electrophoresis and the following in vitro treatment of the isoenzymes with triphenol phos phate (TPP, an inhibitor of carboxylesterase) indicated the TPP-sensitive esterase was mainly distributed in liver of the five species. The enzyme was not found in the other five tissues (including gill) except in gallbladder of topmouth gudgeon and goldfish. The corre lation was obviously improved between susceptibility and detoxification capacity if activity of the TPP-sensitive esterase was employed instead of that of the nonspecific esterase to make the comparison. In vitro treatment of nonspecific esterase in liver with malaoxon proved that the active metabolite of malathion inhibited a different isoenzyme from the TPP-sensitive one.

Correlation between biochemical parameters and susceptibility of freshwater fish to malathion.

Acute toxicity (96-h LC50) of malathion was tested using five species of freshwater fish, namely, topmouth gudgeon (Pseudorasbora parva), goldfish (Carassius auratus), nile tilapia (Tilapia nilotica), mosquitofish (Gambusia affinis), and rainbow trout (Salmo gairdneri). Correlation was found between susceptibility and biochemical parameters such as activity of brain acetylcholinesterase (AChE) and in vitro resistance of the enzyme to inhibition (IC50) of malaoxon (a major metabolite of malathion). The in vitro study also showed that malaoxon instead of malathion was the main inhibitor of AChE. Susceptibility to malathion was considerably changed as the fish was pretreated with piperonyl butoxide (PB, a P-450 inhibitor) and triphenyl phosphate (TPP, an inhibitor of carboxylesterase), respectively. Toxicity of malathion was significantly increased by TPP, but the responses of fish to PB were quite different among species. This suggested that both carboxylesterase and monooxygenase played an important role in susceptibility determination, and great variations existed among species in activity of monooxygenase.

Sensory Analysis of Trout Tainted by Diesel Fuel in Ambient Water

Rainbow trout (Salmo gairdnen) were kept in fresh water tanks for 24 h and exposed to one of seven concentrations of diesel, using a flow-through system with used water discharged to waste. The concentrations ranged from 0.0087 to 0.87 mg.l−1 (0.01 to 1.0 µ1.1−1). An experienced taste panel assessed the degree of taint in the cooked fish by four different procedures. These were the triangular test, three-alternative forced-choice (3-AFC) and two forms of rating scale. The triangular and 3-AFC procedures yielded similar estimates of threshold, the estimate from the combined data being approximately 0.08 mg.l−1. Although the 3-AFC procedure has some advantages, they are not sufficient to recommend it in place of the triangular test. Both methods showed better ability to discriminate low levels of taint than the quantitative rating procedures.

Public Evaluation of Fish Tainting from Pulp and Paper Mill Discharges

As part of the Remedial Action Plan (RAP) programs for the St. Lawrence and Spanish Rivers in Ontario, Canada, tainting evaluations were conducted using members of the Public Advisory Committees (PACs) and the RAP teams. Triangle test sensory evaluations were conducted on caged rainbow trout (Salmo gairdneri) exposed insitu upstream and downstream of the pulp and paper mill diffuser outfalls In the St. Lawrence River only, evaluations were conducted on indigenous yellow perch (Perca flavescens) caught upstream and downstream of the mill discharge . In both locations, the odour of the flesh from the caged trout exposed above the diffuser outfall was not judged significantly different from caged trout exposed downstream of the discharge. However, the indigenous perch caught downstream of the mill in the St. Lawrence River were judged by the panelists to have a significantly more objectionable odour than those caught upstream of the discharge. While the effluent tainting potential appears to have been eliminated in the Spanish River, further studies are required to determine the source and magnitude of tainting concerns in the St. Lawrence River. The sensory test and results reported here provide useful tools for evaluating the tainting potential of pulp mill discharges and for assessing perceived consumer quality of the fish exposed to these effluents.

Hydrothermically treated soy beans as source of dietary protein for rainbow trout(Salmo gairdneri, R.)

(1991). Hydrothermically treated soy beans as source of dietary protein for rainbow trout (Salmo gairdneri, R.). Archiv fur Tierernaehrung: Vol. 41, No. 2, pp. 223-228.

An Analysis of acid vase,ionic and water balance in rainbow trout (salmo gairdneri) exercised at cruising speeds

Rainbow trout (Salmo gairdneri) were exercised at cruising speeds for 5hours. A slight but significant increase in dorsal aortic blood pH after I hour ofexercise was accompanied by significant decreases in PeDl and total C02content of blood. These changes were maintained throughout the exercise periodof 5 hours. This respiratory alkalosis could be due to hyperventilation and/orthe result of increased uptake of Na+ and Cl- which occurred along with theincrease in plasma volume in order to maintain normal osmotic concentrations.The uptake of Na+ and CI- occurred presumably via branchial Na+ /H+ andCI- /HCO2- ion exchange mechanisms.

DNA adducts as early bioindicators of chemical exposure

Sensitive analytical methods indicate the presence of hundreds of chemical contaminants in our environment. However, concentration of these pollutants is usually at the low parts per million or parts per billion level. At such low levels, toxicants induce long-term (chronic) rather than short-term (acute) toxicities. Experiments are designed to evaluate chronic toxicity using early bioindicators. Recently, fish have been used as experimental animals because some species show early (weeks as opposed to years in other research animals), sensitive responses. Thus, medaka (Oryzias latipes), following exposure to diethylnitrosamine (DEN), exhibited liver tumors in several weeks; more interestingly its DNA was modified (to a 'DNA-adduct') after only 24-48 hours exposure. Such adducts show promise as early bioindicators because they are formed within hours of exposure. The formation of DNA-adducts were monitored in medaka and rainbow trout (Salmo gairdneri) exposed to DEN by aqueous or intra-peritoneal routes. Using HPLC-Fluorimetry, O (6)-ethylguanine (O (6)-EtGua) was detected and monitored in acid thermal hydrolysates of DNA isolates. (Detection limit for O (6)-EtGua was as low as 3 ng, 1.7×10(-11) moles). Fourier transform cyclotron resonance mass spectrometry with IR laser desorption/ionization was used advantageously to establish the structure of nucleotides, bases and nucleosides directly, without further cumbersome derivatizations. Other aspects of DNA-adducts are discussed.

Effect of body size on the uptake and bioconcentration of di-2-ethylhexyl phthalate in rainbow trout

Three groups of rainbow trout (Salmo gairdneri) having average body weights of 2.9, 61 and 440 g were exposed at 12°C by the water to di-2-ethylhexyl phthalate (DEHP). The kinetics of uptake and bioconcentration were characterized in each group using a compartmental model. Most of the model parameters, when expressed per unit body weight, were similar in the three sizes of fish. The two major exceptions were the uptake rate parameter, a measure of the capacity of the gill to extract DEHP from water and the apparent size (volume of distribution) of the large DEHP storage compartment, which is a measure of the capacity of the fish to accumulate DEHP. The values of these parameters declined as body weight increased; they followed the allometric equation with body weight exponents of 0.44 and 0.77, respectively. The body weight-associated changes in the pharmacokinetic parameters caused the bioconcentration factor to decline as body weight increased, from 51.5 to 1.6.

Enzyme heterozygosity and growth of rainbow trout reared at two rations

The relationship between heterozygosity at nine enzyme loci and both size and growth in rainbow trout (Salmo gairdneri) reared at either low (LRT) or high (HRT) ration for 84 days is reported. The experimental fish were progeny produced from a pooled mating of 25 female and 25 male rainbow trout captured in spawning condition at the Ganaraska River, Ontario. There is a significant negative regression between the number of heterozygous loci per fish and size (fork length and weight) among fish at the beginning of the experiment. Heterozygotes at two loci, Sod and Mdh3,4, were significantly smaller than homozygotes. A significant negative regression between multilocus heterozygosity and size was detectable among the fish reared at HRT for 84 days but not at LRT. Ration appeared to affect the strength of the association between heterozygosity and growth because at HRT homozygotes at the majority of loci grew faster than heterozygotes, but the reverse was true at LRT.

Endocytosis via the scavenger- and the mannose-receptor in rainbow trout (Salmo gairdneri) pronephros is carried out by nonphagocytic cells

Endocytosis of modified human serum albumin (HSA) and mannose-terminated glycoproteins was studied in pronephros cells from rainbow trout (Salmo gairdneri). Blood clearance and tissue uptake of dinitrophenylated human serum albumin (DNP-HSA) was dependent on the number of DNP-groups conjugated to the albumin molecule. Uptake of DNP35-HSA in isolated pronephros cells was saturable. Pronephros cells also internalized the mannose-terminated glycoprotein invertase by a receptor-mediated process. DNP-HSA and invertase were recovered in the same cell fractions when pronephros cells containing in vivo endocytosed ligands were separated by density gradient centrifugation. The cells endocytosing these ligands were apparently not macrophages. The macrophages were recovered in cell fractions with higher densities. They were identified by their ability to adhere to glass and to carry out phagocytosis. Cultured macrophages did not endocytose chemically modified albumin (DNP-HSA and formaldehyde-treated albumin) and mannose-terminated glycoproteins (ovalbumin) in vitro. These ligands were not recovered in glass adherent pronephros cells after in vivo endocytosis of the proteins. The present data suggest that macrophages in rainbow trout pronephros possess neither the receptor for chemically modified albumin, the scavenger receptor, nor the mannose-specific receptor.

Incorporation and metabolism of (n-3) and (n-6) polyunsaturated fatty acids in phospholipid classes in cultured rainbow trout (Salmo gairdneri) cells

The incorporation and metabolism of various (n-3) and (n-6) polyunsaturated fatty acids supplemented to the culture medium was investigated in the rainbow trout cell line, RTG-2. The distribution, and the occurrence and relative extent of further desaturation and elongation of the incorporated acids was determined in individual phospholipid classes by analysis of the fatty acid compositions. RTG-2 cells exhibited Δ6 and Δ5 desaturase activities whereas Δ4 desaturase activity was almost totally absent. The percentage of precursor acids was greatest in the phosphatidic acid/cardiolipin fraction (PA/CL), suggesting a role for possibly PA in the initial incorporation of these acids into the phospholipid pool. The compositional data indicated that individual intermediates and products of the desaturation pathways were associated with specific phospholipid classes probably via mechanisms depending upon the specificities of the acylating enzymes. The composition of phosphatidylinositol (PI) and the tightly controlled mechanisms for generating/maintaining it are consistent with a role for this phospholipid in providing precursor fatty acid for eicosanoid synthesis.

Comparison of cadmium concentrations in Atlantic salmon (Salmo salar) fry fed different commercial feeds

There has been a tremendous growth of the Norwegian fish farming industry from a production of 7,500 tons of Atlantic salmon (Salmo salar) and rainbow trout (Salmo gairdneri) in 1980 to a production of about 90,000 tonnes (mostly salmon) in 1988. The great economic value of this production has also led to interest in any toxic substance that could possibly reduce fish growth and/or impair fish health. In this study the concentration of cadmium in four commercial feeds for salmon fry and the cadmium concentration in the growing fry fed these diets were studied.

Calmodulin concentration in mucus of rainbow trout,Salmo gairdneri, exposed to combinations of acid, aluminum, and calcium

As a result of increasing acidification in various watersheds elevated levels of aluminum have been observed in soil and surface water. The toxicity of Al to fish has been shown to be positively correlated with the concentration of inorganic monomeric. The exact mechanism(s) of Al toxicity is not fully understood. Recently, the presence of calmodulin (CaM), a calcium-regulating protein, has been reported in fish gills and mucus. Calmodulin selectively binds inorganic monomeric Al causing conformational changes in the protein. Aluminum-induced conformational changes cause a reduction in the ability of calmodulin to mediate Ca-dependent phosphodiesterase and ATPase activity. Calmodulin also plays a key role in coordinating the effects of secondary messenger systems in response to cellular stimulation. Given the involvement of calmodulin in numerous biochemical pathways, its interaction with aluminum may be a key lesion in the broadly defined syndrome of aluminum toxicity. The present study was undertaken to establish a relationship between Al concentration in aqueous solution and the quantity and activity of CaM in the mucus of adult rainbow trout (Salmo gairdneri). Fish were exposed to various levels of pH, Ca, and Al. Mucus was collected and the amount of CaM was determined. The ability of the Al-exposed CaMmore » to activate the phosphodiesterase enzyme system was also evaluated.« less

Gill ATPases activities in domesticated rainbow trout(Salmo gairdneri)at different times of the year

Abstract Seasonal changes on gill ATPases activities of domesticated rainbow trout (Salmo gairdneri ), reared under natural conditions, were studied during 1988. There is a peak in the (Na+‐K+) ATPase activity between May 10th and July 13rd. The highest average activity appears during June, just before and after summer solstice (June 15th and 29th). Ca2+‐, Mg2+‐ and HCO 3‐ATPases show annual significant variations in their activities (p<0.05); nevertheless, none of them present a seasonal pattern. It seems to be that, of all implicated enzymes on ionosmotic regulation, only (Na∗‐K∗)‐ATPase shows circannual variations that can be related to preadaptative changes of the smoltification process.

Measurement of plasma leucine flux in rainbow trout (Salmo gairneri R.) using osmotic pump. Preliminary investigations on influence of diet

A method for the direct measurement of plasma amino acid flux, in rainbow trout, using the continuous infusion of L-[U-(14)C]-leucine with ALZET mini-osmotic pumps implanted into the peritoneal cavity, was developed. The fish were fed successively on three different diets (a commercial control diet, a semi-purified diet and a purified diet) during the 4 weeks of experiment. The amounts of radioactivity in the free pool and the protein of both the plasma and skin mucus were measured in these fish. The total flux of leucine was calculated either from the specific activity of leucine in the plasma (61.8 mg leucine. 100 g(-1).d(-1)) or from the amounts of labelled and unlabelled leucine flowing into the skin mucus protein (61.5 mg leucine. 100g(-1).day(-1)). The total plasma flux was not affected by changes in the diet. The contributions of total leucine oxidation and whole body protein turnover to plasma leucine flux (80% and 20% respectively) were estimated in fish fed the semi-purified diet.

Immunological detection of in vivo aflatoxin B1–DNA adduct formation in rats, rainbow trout and coho salmon

Immunological detection of carcinogen-DNA adducts in organs or tissues should prove a particularly useful approach for monitoring carcinogen exposure, for characterization of carcinogen binding to DNA and for investigating DNA repair processes in vivo. In one of a series of experiments aimed at raising antibodies against several carcinogen-modified DNAs, rabbits were immunized in our laboratory with aflatoxin B1 (AFB1)-modified DNA. After the titer and specificity of the antibodies produced were checked against standards by the enzyme-linked immunosorbent assay (ELISA) method, they were used to investigate DNA extracted from livers of rats and rainbow trout (Salmo mykiss) injected with tritium-labeled AFB1 at doses of 1-2 mg/kg (rats) or 0.1-0.5 mg/kg (rainbow trout). Adduct levels were compared using both radioactivity and ELISA methods. Positive DNA binding could be detected in both rats and rainbow trout by the immunological method at similar levels to those estimated with the radioactive analysis. To throw light on possible mechanisms underlying the wide variation in response to aflatoxins among salmonid fish, DNA extracted from the livers of rainbow trout (susceptible species) and coho salmon (Oncorhynchus kisutch) (less susceptible species) were compared following AFB1 treatment. A high rate of DNA binding was observed in rainbow trout, whereas significantly lower values were evident in coho salmon, suggesting a direct relationship between binding levels and susceptibility to mycotoxin carcinogenicity.

Metal Homeostasis and Metallothionein Induction in Rainbow Trout Hepatocytes Exposed to Cadmium

This study was undertaken to investigate the cellular effects of Cd and metallothionein (MT) metabolism using a primary cell culture system composed of isolated rainbow trout (Salmo gairdneri) hepatocytes. The cells were exposed to 89 nM Cd for 0, 5, 12, 20, 25, 30, 35, and 40 hr at 15 degrees C. The concentration of Cd used did not cause significant cell damage, as estimated by lactate dehydrogenase (LDH) release into the extracellular medium. However, the presence of the metal led to increased cellular levels of calcium within the first 12 hr of incubation. Later, these returned to control values and remained as such for the rest of the examination period. A transient increase in intracellular copper and zinc also occurred during the initial incubation period. In parallel, the hepatocytes were found to accumulate appreciable quantities of Cd, a significant proportion of which were detected in the cytosol. Distribution profiles of cytosolic Cd obtained through Sephadex G-75 chromatography showed that the metal was associated mainly with the high-molecular-weight (HMW) and middle-molecular-weight (MMW) protein fractions. At t = 12 hr, there was a maximum in the proportion of Cd in the MMW fractions, which was accompanied by a decrease in the proportion of Cu in the same fractions. At this time, cellular MT exhibited the highest levels. MMW fractions were further resolved using anion-exchange chromatography. Although Cd was present in the peaks corresponding to MT, the data indicated that these peaks also contained detectable amounts of Cu and Zn.(ABSTRACT TRUNCATED AT 250 WORDS)