Acclimation to Copper by Rainbow Trout, Salmo gairdneri: Physiology

1987 ◽  
Vol 44 (1) ◽  
pp. 99-104 ◽  
Author(s):  
Darrel Jon Laurén ◽  
D. G. McDonald
Keyword(s):  
Rainbow Trout ◽  
Kinetic Parameters ◽  
Maximum Rate ◽  
Sodium Concentration ◽  
Whole Body ◽  
Salmo Gairdneri ◽  
Copper Exposure ◽  
Sodium Efflux ◽  
Sodium Uptake ◽  
Body Sodium

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.

Acclimation to Copper by Rainbow Trout,Salmo gairdneri: Biochemistry

1987 ◽  
Vol 44 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Darrel Jon Laurén ◽  
D. G. McDonald
Keyword(s):  
Rainbow Trout ◽  
Specific Activity ◽  
Gill Tissue ◽  
Microsomal Protein ◽  
Whole Body ◽  
Salmo Gairdneri ◽  
Copper Accumulation ◽  
Copper Exposure ◽  
Copper Uptake ◽  
Liver Copper

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.

WHOLE-BODY SODIUM CONCENTRATION IN LARVAL FATHEAD MINNOWS (PIMEPHALES PROMELAS) DURING AND FOLLOWING COPPER EXPOSURE

2006 ◽  
Vol 25 (6) ◽  
pp. 1635 ◽  
Author(s):  
Holly M. Zahner ◽  
Eric J. VanGenderen ◽  
Joseph R. Tomasso ◽  
Stephen J. Klaine
Keyword(s):  
Pimephales Promelas ◽  
Sodium Concentration ◽  
Whole Body ◽  
Copper Exposure ◽  
Fathead Minnows ◽  
Body Sodium

scholarly journals Adaptational Responses of Rainbow Trout to Lowered External Nacl Concentration: Contribution of the Branchial Chloride Cell

1989 ◽  
Vol 147 (1) ◽  
pp. 147-168 ◽  
Author(s):  
STEVE F. PERRY ◽  
PIERRE LAURENT
Keyword(s):  
Rainbow Trout ◽  
Surface Area ◽  
Fresh Water ◽  
Primary Response ◽  
Chloride Cell ◽  
Whole Body ◽  
Salmo Gairdneri ◽  
Apical Surface ◽  
Ionic Fluxes ◽  
Area 5

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.

Physiological Correlates of Interspecific Variation in Acid Tolerance in Fish

1988 ◽  
Vol 136 (1) ◽  
pp. 243-258 ◽  
Author(s):  
J. FREDA ◽  
D. G. MCDONALD
Keyword(s):  
Yellow Perch ◽  
Acid Tolerance ◽  
Binding Activity ◽  
Low Ph ◽  
Whole Body ◽  
Salmo Gairdneri ◽  
Survival Times ◽  
Ion Regulation ◽  
Sodium Efflux ◽  
Na Efflux

This study investigated ion regulation in relation to water pH in three species of fish of differing tolerance to low pH (common shiners, Notropis cornutus, most sensitive; rainbow trout, Salmo gairdneri, intermediate; yellow perch, Perca flavescens, least sensitive). Increasing sensitivity to exposure to low pH was characterized by shorter survival times, greater losses of whole-body ions, more complete inhibition of Na+ uptake, and greater stimulation of Na+ efflux, the latter being the most important factor in determining survival. Interspecific variations in acid tolerance were also correlated with Na+ transport characteristics at circumneutral pH; Km was directly correlated and Vmax inversely correlated with acid tolerance. In addition, there were large qualitative differences among the species in the Ca2+-dependence of Na+ efflux. Sodium efflux induced by low pH was markedly Ca2+-dependent in both trout and shiners in a manner consistent with a simple competition between Ca2+ and H+ for gill binding sites. The increased sensitivity of shiners relative to trout was related to lowered Ca2+- binding activity. In contrast, Na+ efflux in perch was virtually unaffected by water [Ca2+]. Similarly, La3+ (a Ca2+ antagonist) stimulated higher Na+ losses from shiners than from trout, but had little effect upon perch. Ionic losses produced by saturating La3+ concentrations were generally lower than those produced by H+, suggesting that Ca2+ displacement is not the only mechanism for increased gill permeability at low pH. Nonetheless, the results obtained are consistent with the notion that acid tolerance may be related to Ca2+-binding activity in some species (e.g. trout and shiners) although not in others (e.g. perch).

THE EFFECT OF ADRENOCORTICAL STEROIDS ON THE TISSUE ELECTROLYTE COMPOSITION OF THE FRESH-WATER RAINBOW TROUT (SALMO GAIRDNERI)

1963 ◽  
Vol 25 (4) ◽  
pp. 457-464 ◽  
Author(s):  
W. N. HOLMES ◽  
D. G. BUTLER
Keyword(s):  
Rainbow Trout ◽  
Fresh Water ◽  
Experimental Period ◽  
Sodium Concentration ◽  
Significant Rise ◽  
Salmo Gairdneri ◽  
Plasma Sodium ◽  
Adrenocortical Activity ◽  
Transient Rise ◽  
Sodium And Potassium

SUMMARY The effects were studied of cortisol, corticosterone and aldosterone on the concentrations of sodium and potassium in muscle and blood plasma and on water content of muscle in the fresh-water rainbow trout (Salmo gairdneri). These steroids appeared to cause a loss in plasma sodium throughout the 96 hr. experimental period. An initial rise in muscle sodium was observed during the first 24 hr. after commencement of the treatments. The subsequent decline in muscle sodium was interrupted by a transient rise followed by a continuing decline. The effect of these hormones on the potassium concentrations in plasma was variable, although there was a significant rise in the potassium concentration in muscle during the period of decline in sodium concentration. The significance of these results in relation to the possible enhanced adrenocortical activity of the trout during adaptation to a marine environment is discussed.

Influence of Copper Exposure on Whole-Body Sodium Levels in Larval Fathead Minnows (Pimephales promelas)

2007 ◽  
Vol preprint (2008) ◽  
pp. 1
Author(s):  
Eric VanGenderen ◽  
Joseph Tomasso ◽  
Stephen Klaine
Keyword(s):  
Pimephales Promelas ◽  
Whole Body ◽  
Copper Exposure ◽  
Fathead Minnows ◽  
Body Sodium

Diminished social status affects ionoregulation at the gills and kidney in rainbow trout (Oncorhynchus mykiss)

2004 ◽  
Vol 61 (4) ◽  
pp. 618-626 ◽  
Author(s):  
Katherine A Sloman ◽  
Graham R Scott ◽  
D Gordon McDonald ◽  
Chris M Wood
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Social Status ◽  
Metabolic Cost ◽  
Whole Body ◽  
Sodium Reabsorption ◽  
Plasma Sodium ◽  
Sodium Efflux ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Uptake Rates

Competition for social status can result in physiological differences between individuals, including differences in ionoregulatory ability. Subordinate rainbow trout (Oncorhynchus mykiss) had two-fold higher uptake rates of sodium across the gill and two-fold higher whole-body sodium efflux rates than the dominant fish with which they were paired. Sodium efflux was then divided into branchial and renal components, both of which were higher in subordinates. Branchial sodium efflux accounted for 95%–98% of sodium loss. Plasma sodium concentrations were more variable, although not significantly different, in subordinate fish, suggesting that the increased loss of sodium in these trout is compensated for by an increase in uptake rates. Urine flow rates and plasma cortisol concentrations were higher in subordinate fish, but there was no difference in glomerular filtration rate between dominants and subordinates. Renal sodium reabsorption was significantly reduced in subordinates. In summary, the ionoregulation of subordinate individuals was altered, most likely occurring as a result of stress-induced changes in gill permeability, resulting in a higher throughput of water and increased branchial sodium efflux. These changes in ionoregulatory ability have many physiological implications, including the increased susceptibility of subordinates to ionoregulatory challenges and an increased metabolic cost of ionoregulation.

scholarly journals The Effect of External Sodium and Calcium Concentrations on Sodium Fluxes by Salt-Depleted and Non-Depleted Minnows, Phoxinus Phoxinus (L.)

1987 ◽  
Vol 131 (1) ◽  
pp. 417-425
Author(s):  
W. J. FRAIN
Keyword(s):  
Sodium Concentration ◽  
Uptake Mechanism ◽  
Sodium Influx ◽  
Sodium Efflux ◽  
Sodium Uptake ◽  
Km Value ◽  
Concentration Changes ◽  
The Relationship ◽  
Very High ◽  
External Calcium

The relationship between sodium influx and external sodium concentration in Phoxinus is complex and unusual. In non-depleted fish the relationship is approximately that given by the Michaelis-Menten equation of enzyme kinetics. However, the Km value (a measure of the affinity of the sodium uptake mechanism for sodium) is very high (3mmoll−1), indicating a low affinity of the uptake mechanism for sodium. On sodium depletion, the relationship between sodium influx and external sodium concentration changes to produce a curve which has a stepped appearance, and is unusual in that the maximum influx is not increased above that in non-depleted fish. The overall Km alters very little; however, the Km for the lower part of the curve is very low (0.05 mmoll−1). A model is proposed to explain these results in the form of two sodium uptake mechanisms working in parallel across the gill. The second carrier is only active when the fish is sodium-depleted and kept in low external sodium concentrations. Neither the external sodium concentration nor the external calcium concentration has any direct effect on sodium efflux. However, fish depleted in 1 mmoll−1 calcium have a lower sodium efflux than fish depleted in distilled water. Calcium appears to reduce the permeability of the gill to ions such as sodium. Since calcium has no effect on sodium influx, changes in gill permeability do not involve the sodium influxmechanism.

scholarly journals On the Mechanism of Sodium Extrusion across the Irrigated Gill of Sea Water-Adapted Rainbow Trout (Salmo gairdneri)

1974 ◽  
Vol 64 (2) ◽  
pp. 148-165 ◽  
Author(s):  
Leonard B. Kirschner ◽  
Lewis Greenwald ◽  
Martin Sanders
Keyword(s):  
Rainbow Trout ◽  
Active Component ◽  
Sea Water ◽  
Salmo Gairdneri ◽  
Sodium Efflux ◽  
Exchange Diffusion ◽  
The Difference ◽  
Sodium Extrusion ◽  
Trout Gill ◽  
Electrical Data

Sodium efflux (JoutNa) across the irrigated trout gill was rapid in sea water (SW), but only about 25 % as large in fresh water (FW). The difference correlated with a change in the potential difference across the gill (TEP). The latter was about +10 mV (blood positive) in SW, but –40 mV in FW. Both flux and electrical data indicated that gills in this fish are permeable to a variety of cations including Na+, K+, Mg2+, choline, and Tris. They are less permeable to anions; PNa:PK:PCl was estimated to be 1:10:0.3, and PCl > Pgluconate. The TEP was shown to be a diffusion potential determined by these permeabilities and the extant ionic gradients in SW, FW as well as in other media. JoutNa appeared to be diffusive in all of the experiments undertaken. Exchange diffusion need not be posited, and the question of whether there is an active component remains open.

Branchial Ionic Uptake and Acid-Base Regulation in the Rainbow Trout, Salmo Gairdneri

1981 ◽  
Vol 92 (1) ◽  
pp. 289-303
Author(s):  
S. F. PERRY ◽  
M. S. HASWELL ◽  
D. J. RANDALL ◽  
A. P. FARRELL
Keyword(s):  
Rainbow Trout ◽  
Sodium Bicarbonate ◽  
Salmo Gairdneri ◽  
Hypercapnic Acidosis ◽  
Acid Base ◽  
Bathing Medium ◽  
Sodium Uptake ◽  
Chloride Uptake ◽  
Disulphonic Acid ◽  
Ionic Uptake

1. Amiloride (10−4 M) inhibited sodium uptake in rainbow trout by 78% and was associated with a pronounced acidosis and decreases in both plasma total CO2 (Tcoco2)* and [HCO3−]. 2. 4-acetamido-4′-iso-thiocyanatostilbene-2,2′ disulphonic acid (SITS) (10−4M) in the bathing medium inhibited chloride uptake by 66% and following 6 h a significant decrease in plasma [H+] and significant increases in TCOCO2 and [HCO3−] were observed. 3. Inhibition of chloride uptake (50%) with external sodium bicarbonate (12 mM) resulted in a more rapid and pronounced alkalosis than did SITS inhibition. 4. Hypercapnic acidosis had no significant effect on the rates of branchial sodium and chloride uptake. 5. Increasing the concentration of sodium in the bathing water resulted in a less pronounced acidosis and a more rapid pH recovery during hypercapnia. 6. These results are discussed with reference to the gill as an acid-base regulating structure. These findings are consistent with a gill model previously presented by Haswell, Randall & Perry (1980).

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