Acclimation to Copper by Rainbow Trout,Salmo gairdneri: Biochemistry

1987 ◽  
Vol 44 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Darrel Jon Laurén ◽  
D. G. McDonald

Whole body, gill, and liver copper uptake, gill Na+-K+-ATPase specific activity, and gill and liver acid-soluble thiols (AST), glutathione, and cysteine of rainbow trout (Salmo gairdneri) were measured during 28 d of exposure to 55 μg copper∙L−1. Na+-K+-ATPase specific activity was inhibited by 33% within 24 h of copper exposure, but this was compensated by a significant increase in microsomal protein so that the total Na+-K+-ATPase activity per milligram of gill tissue returned to normal by day 14. There was no accumulation of copper and no increase in AST, glutathione, or cysteine in the gill. However, after 7 d of exposure, hepatic AST and glutathione had increased by about 2 times, and a sulfhydryl-rich, acid-soluble protein, tentatively identified as metallothionein, increased by 2.8 times. Copper accumulation was highest in the liver, but other tissues also accumulated copper.

1985 ◽  
Vol 118 (1) ◽  
pp. 277-286 ◽  
Author(s):  
F. B. EDDY

Potassium turnover was studied in rainbow trout, Salmo gairdneri Richardson, adapted to fresh water or 22% sea water using 42K and 86Rb. Potassium space of the whole body increased with time and was about 5 mmol kg−1 after 20h, while Rb+ space under the same conditions was only about 0.5 mmol kg−1, indicating slow penetration of body K+ by Rb+, especially in muscle and red blood cells. Potassium influx, measured by decrease in specific activity of the medium, was 0.07 mmol kg−1 h−1 in fresh water and 0.48 mmol kg−1 h−1 in 22 % sea water; the values for efflux were comparable, indicating that unfed fish are able to maintain K+ balance. In both fresh water and dilute sea water, K+ fluxes are 5% or less of the simultaneous Na+ and Cl− fluxes. The mechanism for K+ fluxes is discussed in terms in K+-ATPases.


1988 ◽  
Vol 45 (6) ◽  
pp. 1045-1053 ◽  
Author(s):  
Michael A. Giles

Adult rainbow trout, Salmo gairdneri, were exposed to 3.6 and 6.4 μg Cd/L for 178 d. Cadmium accumulated most rapidly in gill tissue which became saturated at levels 100-fold higher than controls within 24 and 52 d in the high- and low-metal exposures, respectively. Liver cadmium increased 250- to 400-fold over the test period but accumulation exhibited a plateau between 52 and 129 d followed by a rapid rise by 178 d. Kidney cadmium increased consistently throughout the test period to levels approximately 50- to 100-fold higher than control values. Cadmium in the gut and skin increased 10- and 5-fold, respectively, while no increase was recorded in white muscle. A maximum of 2.1% of the cadmium available in a commercial diet (0.2 μg Cd/g dry food} was accumulated in control fish. Although cadmium was not detected in the urine, urinary zinc excretion was elevated in trout exposed to 6.4 μg Cd/L such that 7 mol of zinc was excreted per 1 mol of cadmium accumulated during the initial 24 d of exposure. The whole-body burden of cadmium increased linearly with time in both treatments with a time constant of 0.366 and 0.554%/d for trout exposed to 3.6 and 6.4 μg Cd/L, respectively.


1987 ◽  
Vol 44 (1) ◽  
pp. 99-104 ◽  
Author(s):  
Darrel Jon Laurén ◽  
D. G. McDonald

Juvenile rainbow trout (Salmo gairdneri) were exposed to 55 μg copper∙L−1 for 28 d and then transferred to uncontaminated water for 7 d. Whole body sodium concentration and sodium uptake (Jin) were measured at weekly intervals; Jin was measured at various Na+ concentrations and kinetic parameters estimated. After 24 h of copper exposure, the maximum rate of sodium uptake (Jmax) was inhibited by 55%, the affinity for sodium (Km) reduced by 49%, and whole body Na+ decreased by about 12.5%. After 7 d of exposure, whole body Na+ had returned to control values, but Jmax was still inhibited by 41%. Recovery of whole body Na+ occurred largely by a reduction of sodium efflux (Jout). Both Jmax and Km continued to recover until day 28, at which time Jin had returned to control values. We conclude that acclimation to sublethal copper depends on changes in both Na+ transport and permeability.


1989 ◽  
Vol 147 (1) ◽  
pp. 147-168 ◽  
Author(s):  
STEVE F. PERRY ◽  
PIERRE LAURENT

1. Whole-body ionic fluxes and gill chloride cell (CC) morphology were monitored in rainbow trout (Salmo gairdneri) exposed acutely or chronically to natural fresh water (NFW; [Na+]=0.120 mmoll−1; [Cr]=0.164 mmoll−1) or artificially prepared fresh water with reduced [NaCl] (AFW; [Na+]=0.017 mmoll−1; [CT]=0.014 mmoll−1). 2. Net fluxes of Na+ (JnetNa) and Cl− (JnetCl) became extremely negative (indicating net NaCl loss to the environment) upon immediate exposure to AFW exclusively as a result of reduced NaCl influx (JinNa and JinNa). JnetNa and JnetCl were gradually restored to control rates during prolonged (30 days) exposure to AFW. 3. The restoration of JnetCl in AFW was due both to increased JinCl and to reduced Cl− efflux (JoutCl) whereas the primary response contributing to the restoration of JnetNa a t was an increase of JNain. 4. The total apical surface area of branchial CCs exposed to the external environment increased markedly after 24 h in AFW and remained elevated for 1 month as a consequence of enlargement of individual CCs and, to a lesser extent, increased CC density. JinNa and JinNa were correlated significantly with total CC apical surface area. 5. Plasma cortisol levels rose transiently in fish exposed to AFW. Treatment of NFW-adapted fish with cortisol for 10 days (a protocol known to cause CC proliferation) caused pronounced increases in JinCl and JinNa, as measured in both NFW and AFW. 6. These results suggest that an important adaptational response of rainbow trout to low environmental [NaCl] is cortisol-mediated enlargement of branchial epithelial CCs which, in turn, enhances the NaCl-transporting capacity of the gill as a result of the proliferation of Na+ and Cl− transport sites.


1986 ◽  
Vol 43 (8) ◽  
pp. 1664-1667 ◽  
Author(s):  
J. M. McLeese ◽  
E. Don Stevens

Specific activity and kinetic constants of trypsin from the pyloric caeca of two strains of rainbow trout, Salmo gairdneri, were measured using α-N-benzoyl-DL-arginine-ρ-nitroaniline∙HCl No increase in activity was observed with cold acclimation, suggesting that cold acclimation induces no increase in trypsin concentration. The apparent Km for the substrate was independent of assay temperature over the physiological range in both strains, probably to maintain high rates of catalysis at higher temperatures when nutrient requirements are high. Strain A trout produced a trypsin with lower affinity on cold acclimation, but Strain B trout did not. The two strains differed in intestinal morphology as well as in the characteristics of their trypsins.


Author(s):  
MS Alam Sarker ◽  
Shuichi Satoh

A laboratory based 2 × 2 factorial experiment was conducted to investigate the influence of dietary phosphorus and zinc levels on whole body mineral, liver mineral, and liver vitamin-C contents of fingerling rainbow trout for 21 weeks. Two levels of phosphorus (19 and 30 mg g-1) and two levels of zinc (55 and 100 μ g g-1) in the dry diets were tested. Duplicate tanks of 30 rainbow trout (average weight 1.56 ± 0.24 g) per 60L glass tank were fed experimental diets three times a day to satiation level in 15 to 24oC water temperature. The result of the present study demonstrated that dietary zinc supplementation significantly influenced the whole body zinc and liver copper contents in fingerling rainbow trout where as additional phosphorus did not show any significant difference. Zinc supplementation significantly influenced the liver vitamin-C contents of the fish. Hence it is clear that zinc supplementation is necessary in fingerling rainbow trout feed. Further studies in this area are needed broadly. Key words: Phosphorus, zinc, whole body, liver mineral, liver vitamin-C, rainbow trout DOI = 10.3329/jard.v5i1.1470 J Agric Rural Dev 5(1&2), 135-142, June 2007


1988 ◽  
Vol 45 (2) ◽  
pp. 287-293 ◽  
Author(s):  
K. G. Doe ◽  
W. R. Ernst ◽  
W. R. Parker ◽  
G. R. J. Julien ◽  
P. A. Hennigar

Three pesticides, fenitrothion, 2,4-D, and aminocarb, were tested in static 96-h acute lethal toxicity tests using fingerling rainbow trout (Salmo gairdneri) at pH 4.6, 5.6, 6.9, and 8.5. The toxicity of aminocarb, a base, increased significantly with increasing pH. Conversely, the toxicity of the acidic pesticide 2,4-D increased with decreasing pH. The toxicity of the neutral pesticide fenitrothion did not change significantly with changing pH. Subsequent tests were performed on trout fingerlings with aminocarb to determine the effect of two exposure pH's on brain acetylcholinesterase activity and whole-body aminocarb residue. Brain acetylcholinesterase was found to be inversely proportional to whole-body aminocarb content of fish. In fish exposed at pH 4.6, brain acetylcholinesterase was maximally depressed at 6 h, after which it recovered to within the control range. Whole-body aminocarb concentrations rose to a maximum within 6 h and subsequently declined to low levels. In fish exposed at pH 8.2, brain acetylcholinesterase dropped below the control range by 1 h and remained low until all fish died by 72 h. A maximum whole-body aminocarb concentration was reached within 1 h and remained elevated until the fish died. Several explanations for the observed results are presented.


1982 ◽  
Vol 39 (9) ◽  
pp. 1243-1251 ◽  
Author(s):  
Peter V. Hodson ◽  
D. George Dixon ◽  
Douglas J. Spry ◽  
D. M. Whittle ◽  
John B. Sprague

Three experiments were undertaken to test the null hypotheses that increasing fish size and growth rate do not increase the rate of intoxication of fish by lead. The first experiment demonstrated that there were no significant correlations between weight of fish and either whole-body or blood lead concentrations in feral lake trout (Salvelinus namaycush). The whole-body lead concentration of rainbow smelt (Osmerus mordax) was, however, negatively correlated to wet weight.During the second experiment, an 8-d laboratory exposure of rainbow trout (Salmo gairdneri) to 100 μg/L of total waterborne lead caused a greater uptake of lead by opercular bone in small fish than in larger fish. No relationship was apparent between fish weight and uptake of lead by blood.Chronic exposure of juvenile rainbow trout to lead results in the development of black tails, a symptom of neurotoxicity. The final experiment related the incidence and prevalence of black tails to size and growth rate (ration level) of juvenile rainbow trout chronically exposed to 543 μg/L of total waterborne lead starting with the sac-fry stage. At weights below a common threshold size of 1.5–2.5 g, no black tails occurred; above this threshold the incidence of black tails was a function of growth rate, i.e. the rate at which fish reached the threshold size. The prevalence of black tails was always less in slowly growing fish.These experiments demonstrated that the rate of intoxication by lead, as indicated by uptake rates into tissues and the incidence and prevalence of a symptom of neurotoxicity, did not increase with fish size, but rather with growth rate.Key words: fish, toxicity, lead, fish size, growth rate, neurotoxicity, uptake


1984 ◽  
Vol 41 (11) ◽  
pp. 1592-1600 ◽  
Author(s):  
Karl D. Shearer

By examining a group of rainbow trout (Salmo gairdneri) over their life cycle (ova to 1500 g), 1 found that their elemental composition was determined by fish size, stage of life cycle (prefeeding, juvenile, post-juvenile), and reproductive state. Fish were fed practical diets and were reared under hatchery conditions. Whole body elemental concentrations of Ca, Cu, Fe, K, Mg, Mn, Na, P, Sr, and Zn were size dependent prior to sexual maturity. Rates of elemental accumulation in relation to weight gain were higher in juveniles than in adult fish. Reduced somatic concentrations of Mn, Fe, and Zn were observed during gonad maturation in female but not in male trout. Tissue concentrations of some elements remained constant over the duration of the study, while others increased or decreased linearly with increasing fish size. Tables and equations 1 present will enable the normal tissue and whole body elemental composition of rainbow trout at any size to be determined. My results indicate that body burden or wet weight concentration are better indicators of elemental status than dry weight concentration and that comparison of elemental levels between treatment groups in dietary experiments should be made on the basis of a standard-sized fish or by comparing the rates of elemental deposition with growth.


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