Electrolyte and Water Balance in Plasma and Urine of Rainbow Trout (Salmo gairdneri) during Chronic Exposure to Cadmium

1984 ◽  
Vol 41 (11) ◽  
pp. 1678-1685 ◽  
Author(s):  
Michael A. Giles
Keyword(s):  
Renal Function ◽  
Rainbow Trout ◽  
Water Balance ◽  
Chronic Exposure ◽  
Plasma Calcium ◽  
Salmo Gairdneri ◽  
Plasma Sodium ◽  
Sodium Potassium ◽  
Urine Production ◽  
Calcium And Magnesium

Rainbow trout (Salmo gairdneri) were exposed to 3.6 and 6.4 μg Cd/L for periods up to 178 d. Transitory changes in plasma calcium and magnesium were observed in fish exposed to 3.6 μg Cd/L although the differences were not significant. Exposure to 6.4 μg Cd/L, however, resulted in significantly lowered plasma sodium, potassium, calcium, and chloride and elevated magnesium concentrations. Analyses of urine indicated that the rate of urine production, osmolality, and sodium, potassium, chloride, magnesium, calcium, and protein concentrations were unaffected by exposure to 3.6 μg Cd/L although slight changes were observed in the first week of exposure. Urine production rate and urinary concentrations of potassium and chloride were unaffected in trout exposed to 6.4 μg Cd/L but sodium, protein, and osmolality were elevated and calcium and magnesium concentrations reduced in these fish. The results demonstrate that the majority of the cadmium-induced electrolyte imbalances do not result from impairment of renal function.

The involvement of calcitonin in the reproductive physiology of the rainbow trout

1986 ◽  
Vol 108 (1) ◽  
pp. 17-23 ◽  
Author(s):  
B. Th. Björnsson ◽  
C. Haux ◽  
L. Förlin ◽  
L. J. Deftos
Keyword(s):  
Rainbow Trout ◽  
Plasma Levels ◽  
Sharp Decrease ◽  
Plasma Calcium ◽  
Reproductive Physiology ◽  
Salmo Gairdneri ◽  
Blood Calcium ◽  
High Production Rate ◽  
Calcium And Magnesium ◽  
Free Plasma

ABSTRACT Plasma from rainbow trout (Salmo gairdneri) of both sexes was sampled every month throughout an annual reproductive cycle in order to elucidate possible relationships between plasma calcitonin and free and protein-bound calcium and magnesium. This was then studied in greater detail around the time of ovulation in the female fish. The plasma levels of the parameters studied were stable in males during the whole annual cycle and were similar to the levels found in females during at least 6 months of the cycle. Plasma levels of protein-bound calcium and magnesium as well as calcitonin were raised in the females for 6, 4 and 3 months respectively. These increases occurred concomitantly during the months before and after ovulation, but no correlations between the protein-bound ion and calcitonin levels were found during this period. With the exception of a decrease observed in December, the free plasma levels of calcium and magnesium were stable in both males and females throughout the cycle. This decrease was attributed to the high production rate of the yolkprotein precursor vitellogenin, which binds both calcium and magnesium. In the detailed study on the ovulating females, plasma calcitonin levels were high 4 weeks before, and continued to increase until the time of ovulation, when a sharp decrease towards normal was noted. The free plasma calcium and magnesium levels were not affected, while the protein-bound levels of calcium and magnesium were found to decline towards normal for the duration of the experiment, without any obvious correlation with the time of ovulation. Regulation of calcitonin secretion seems not to be directly related to free plasma calcium levels, and it is suggested that ovarian steroids and/or gonadotrophins are involved. It is still possible, however, that calcitonin in rainbow trout may play a role in protecting the skeleton during periods of the increased calcium demand of oogenesis. It is concluded that calcitonin plays a specific role in the reproductive physiology in female rainbow trout, which is apparently not reflected by measurable changes in blood calcium. J. Endocr. (1986) 108, 17–23

Extrathyroidal Effects of Low Concentrations of Thiourea on Rainbow Trout, Salmo gairdneri

1981 ◽  
Vol 38 (10) ◽  
pp. 1283-1285 ◽  
Author(s):  
J. G. Eales
Keyword(s):  
Rainbow Trout ◽  
Chronic Exposure ◽  
Degradation Rate ◽  
Salmo Gairdneri ◽  
Low Concentrations ◽  
Direct Sensitivity ◽  
Distribution Spaces ◽  
Circulating Levels

Chronic exposure of fed immature rainbow trout (Salmo gairdneri) to a low ambient thiourea (TU) concentration did not depress circulating levels of T4 (thyroxine) or triiodothyronine, T4 degradation rate, or T4 deiodination rate indicating no significant T4 influence on thyroidal hormone output. However, TU increased the hematocrit and decreased distribution spaces for iodide and T4, indicating direct sensitivity of extrathyroidal processes to TU.Key words: thiourea, thyroxine, hematocrit, iodide metabolism, rainbow trout

Onset and rate of drinking in rainbow trout (Salmo gairdneri) following transfer to dilute seawater

1979 ◽  
Vol 57 (10) ◽  
pp. 1863-1865 ◽  
Author(s):  
Roger M. Evans
Keyword(s):  
Rainbow Trout ◽  
Water Balance ◽  
Water Loss ◽  
Sea Water ◽  
Direct Method ◽  
Anguilla Japonica ◽  
Japanese Eel ◽  
Salmo Gairdneri ◽  
Normal Water ◽  
A Direct Method

Seawater-adapted teleosts drink to offset water loss by osmosis. A direct method of monitoring drinking by implanting a fistula to drain the stomach indicated that rainbow trout began drinking from about 9 to 12 (range 1 to 22) h after being placed in 15‰ sea water. Unlike the Japanese eel (Anguilla japonica). in which the onset of drinking has been shown to be immediate and reflex-like, the onset of drinking in trout appears to occur only after appreciable water has been lost to the medium. The trout resembles the eel in that the capacity to shallow water in the absence of postingestional negative feedback exceeds the rate of drinking required to maintain normal water balance.

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.

Ecophysiology and Mercury Accumulation of Rainbow Trout (Salmo gairdneri) When Exposed to Mercury in Various Concentrations of Chloride

1986 ◽  
Vol 43 (3) ◽  
pp. 710-714 ◽  
Author(s):  
Barbara Z. Walczak ◽  
U. Theodore Hammer ◽  
P. Ming Huang
Keyword(s):  
Rainbow Trout ◽  
Chloride Concentration ◽  
Plasma Potassium ◽  
Salmo Gairdneri ◽  
Plasma Sodium ◽  
Mercury Accumulation ◽  
Cell Counts ◽  
Plasma Sodium Level ◽  
White Blood Cell Counts ◽  
Chloride Concentrations

Rainbow trout (Salmo gairdneri) mortality was 100% when exposed to HgCl2 (2–10 μg∙Hg2+∙L−1) for 14 d in a natural low chloride medium. There was no mortality if the medium contained 100, 200, or 400 mg Cl−∙L−1 or more. Accumulation of mercury was highest in kidneys (0.65–13 μg∙g−1), spleen (0.31–4.2), gills (0.46–4.15), and liver (0.53–2.1) but accumulations differed for periods of exposure (14 or 42 d) and chloride concentration in the medium (100 or 200 mg Cl−∙L−1). In rainbow trout exposed to HgCl2 for 42 d, there were significant increases in plasma sodium level at 200 mg Cl−∙L−1 and significant decreases in plasma potassium, albumin, α1-globulin, and β-globulin levels in 100 mg Cl−∙L−1. No significant changes occurred in these parameters at other chloride concentrations or in erythrocytes, hematocrit, mean corpuscular volume, white blood cell counts, or chloride plasma levels. Although chloride concentrations in the media affect mercury accumulation by different organs as well as affecting physiological functions, there appears to be no direct relationship except for reduced mortality.

Effect of Prior Acid Exposure on Physiological Responses of Juvenile Rainbow Trout (Salmo gairdneri) to Acute Handling Stress

1985 ◽  
Vol 42 (4) ◽  
pp. 710-717 ◽  
Author(s):  
Bruce A. Barton ◽  
Gary S. Weirter ◽  
Cars B. Schreck
Keyword(s):  
Rainbow Trout ◽  
Plasma Glucose ◽  
Plasma Cortisol ◽  
Acid Stress ◽  
Peak Level ◽  
Acid Exposure ◽  
Salmo Gairdneri ◽  
Plasma Sodium ◽  
Handling Stress ◽  
Juvenile Rainbow Trout

Acid-stressed fish appear to be more sensitive to additional stressors than unstressed fish. When juvenile rainbow trout, Salmo gairdneri, were exposed to acid conditions (pH 5.7–4.7) for 5 d, plasma cortisol was affected only slightly during the initial hours of exposure, but plasma glucose and hematocrit increased, and plasma sodium decreased. However, when fish held at pH 4.7 were subsequently subjected to a 30-s handling stress, poststress plasma cortisol rose to a peak level of more than twice that in handled fish held at ambient pH (6.6). Effects of handling on plasma glucose or sodium were not apparent against levels already altered by the chronic acid exposure, judging by the corticosteroid response, we conclude that the acid-stressed fish were more sensitive to additional handling, even though they appeared to be physiologically normal after 5 d. Thus, as a management consideration, when fish are stocked in acidified waters, care should be taken to avoid situations where the fish may encounter additional disturbances in the new environment. Plasma glucose and sodium were better indicators of chronic acid stress alone than plasma cortisol, but the greater cortisol response to handling at low pH may be a useful method of detecting increased interrenal activity during early stages of environmental acidification.

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