Changes in plasma insulin and carbohydrate metabolism of zinc-stressed rainbow trout, Salmo gairdneri

1982 ◽  
Vol 60 (9) ◽  
pp. 2079-2084 ◽  
Author(s):  
G. F. Wagner ◽  
B. A. McKeown
Keyword(s):  
Rainbow Trout ◽  
Pancreatic Beta Cells ◽  
Plasma Insulin ◽  
Zinc Sulphate ◽  
Liver Glycogen ◽  
Salmo Gairdneri ◽  
Control Group ◽  
Exposed Fish ◽  
Glucose Levels ◽  
Insulin Radioimmunoassay

An experiment was conducted to determine if the hyperglycemia that is observed in zinc-stressed fish is also accompanied by changes in the levels of plasma insulin and liver glycogen. Juvenile rainbow trout were exposed to three concentrations of zinc sulphate along with a control group over 31 days. Plasma glucose levels were monitored in each group over the course of the experiment. The group demonstrating the most acute and sustained hyperglycemia (0.352 ppm zinc) was then analyzed along with the controls for changes in plasma insulin (using a teleost insulin radioimmunoassay) and liver glycogen levels. Significant depressions in plasma insulin and liver glycogen levels were observed in the zinc-exposed fish when compared with the controls. These changes are discussed with respect to possible influences of epinephrine, which is elevated in stressed fish, and (or) a direct effect of zinc metal on the pancreatic beta cells.

scholarly journals Chronic cortisol and the regulation of food intake and the endocrine growth axis in rainbow trout

2015 ◽  
Vol 226 (2) ◽  
pp. 103-119 ◽  
Author(s):  
Barry N Madison ◽  
Sara Tavakoli ◽  
Sarah Kramer ◽  
Nicholas J Bernier
Keyword(s):  
Rainbow Trout ◽  
Food Intake ◽  
Mass Gain ◽  
Liver Glycogen ◽  
Mrna Levels ◽  
Muscle Lipid ◽  
Glucose Levels ◽  
Treated Fish ◽  
Plasma Gh ◽  
Post Implantation

To gain a better understanding of the mechanisms by which cortisol suppresses growth during chronic stress in fish, we characterized the effects of chronic cortisol on food intake, mass gain, the expression of appetite-regulating factors, and the activity of the GH/IGF axis. Fish given osmotic pumps that maintained plasma cortisol levels at ∼70 or 116 ng/ml for 34 days were sampled 14, 28 and 42 days post-implantation. Relative to shams, the cortisol treatments reduced food intake by 40–60% and elicited marked increases in liver leptin (lep-a1) and brain preoptic area (POA) corticotropin-releasing factor (crf) mRNA levels. The cortisol treatments also elicited 40–80% reductions in mass gain associated with increases in pituitarygh, liverghreceptor (ghr), liverigfIandigfbinding protein (igfbp)-1 and -2 mRNA levels, reduced plasma GH and no change in plasma IGF1. During recovery, while plasma GH and pituitarygh, liverghrandigfIgene expression did not differ between treatments, the high cortisol-treated fish had lower plasma IGF1 and elevated liverigfbp1mRNA levels. Finally, the cortisol-treated fish had higher plasma glucose levels, reduced liver glycogen and lipid reserves, and muscle lipid content. Thus, our findings suggest that the growth-suppressing effects of chronic cortisol in rainbow trout result from reduced food intake mediated at least in part by increases in liverlep-a1and POAcrfmRNA, from sustained increases in hepaticigfbp1expression that reduce the growth-promoting actions of the GH/IGF axis, and from a mobilization of energy reserves.

Normal Ranges for Diagnostically Important Hematological and Blood Chemistry Characteristics of Rainbow Trout (Salmo gairdneri)

1983 ◽  
Vol 40 (4) ◽  
pp. 420-425 ◽  
Author(s):  
W. Roscoe Miller III ◽  
Albert C. Hendricks ◽  
John Cairns Jr.
Keyword(s):  
Rainbow Trout ◽  
Blood Chemistry ◽  
Serum Glucose ◽  
Salmo Gairdneri ◽  
Total Serum Protein ◽  
Total Serum ◽  
Tolerance Interval ◽  
Glucose Levels ◽  
Normal Ranges ◽  
Nonparametric Techniques

Wytheville strain rainbow trout (Salmo gairdneri) were used in an 11-mo study designed to establish normal ranges for several hematological and blood chemistry characteristics. Two nonparametric techniques, percentile estimation and tolerance interval, were used and produced comparable ranges to those based on the Gaussian distribution. Serum glucose levels appeared to coincide with the condition of the gonads; low glucose levels corresponded with approximate spawning times at the hatchery. Total serum protein and gonadal condition were similarly related. High variability of the serum enzymes LDH and SGOT was partially explained by a positive linear relationship between enzyme activity and acclimation temperatures. In addition to physiological significance, determination of normal ranges for rainbow trout has promise in diagnosis of pathological, disease, and toxicant-induced stresses.

Endrin Toxicosis in Rainbow Trout (Salmo gairdneri)

1973 ◽  
Vol 30 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Blake F. Grant ◽  
Paul M. Mehrle
Keyword(s):  
Rainbow Trout ◽  
Total Protein ◽  
Serum Cortisol ◽  
Liver Glycogen ◽  
Salmo Gairdneri ◽  
Protein Distribution ◽  
Serum Electrolytes ◽  
Electrophoretic Patterns ◽  
Sublethal Doses ◽  
High Doses

In mature rainbow trout (Salmo gairdneri) receiving sublethal doses of endrin (4.3–145 × μg/kg body wt/day in 0.215–7.25 mg/kg of food) for 163 days and then forced to swim for 1 hr, the insecticide affected serum electrolytes, osmolality, total protein, cholesterol, cortisol, lactate, glucose, liver glycogen, and growth. Forced swimming alone altered 9 of 16 serum parameters examined. Apparent increases in serum Na and Cl and significant increases in osmolality and liver glycogen were directly related to dosage. A biphasic distribution of phosphate, total protein, and cholesterol with dosage was apparent. Glucose was increased about 50% by 145 μg/kg but was unaffected by lower doses. Variance analysis of zone electrophoretic patterns disclosed an in teraction between serum protein distribution and dose. Mobilization of liver glycogen was apparently inhibited by low doses and almost totally blocked by high doses. Correspondingly, trout given 14.5 μg/kg or more had lowered serum cortisol levels whereas the lowest dose elevated cortisol. Growth was inhibited appreciably by 145 μg/kg but not by lower doses. Visceral fat accumulated 4.8–8.7 μg endrin/g tissue in the 43 and 145 μg/kg exposures. We conclude that endrin caused dysfunction of physiologic processes critical to survival.

Investigation sur la toxicodynamique du cyanure et sur sa biotransformation chez la truite arc-en-ciel (Salmo gairdneri)

1986 ◽  
Vol 43 (10) ◽  
pp. 2017-2024 ◽  
Author(s):  
Pierre Raymond ◽  
Gérard Leduc ◽  
Jack A. Kornblatt
Keyword(s):  
Rainbow Trout ◽  
Blood Plasma ◽  
Cytochrome Oxidase ◽  
Liver Glycogen ◽  
Effective Concentration ◽  
Salmo Gairdneri ◽  
Pasteur Effect

The exposure of rainbow trout (Salmo gairdneri) to 0.01, 0.02 and 0.03 mg HCN∙L−1 for 20 d demonstrated the biotransformation of HCN into thiocyanate which accumulated in the blood plasma which increased the duration of exposure to cyanide. Despite its transformation into thiocyanate, there is still a sufficient quantity of cyanide to inhibit cytochrome oxidase by 60–80% within the first 24 h of exposure. This level of inhibition remained stable during the 20 d of the tests and was the same at the three concentrations tested. This observation permits the prediction of effective concentration of free HCN inside the fish. The measurements of liver glycogen levels illustrate the Pasteur effect in the rainbow trout subjected to cyanide. During cyanide exposure, liver glycogen was rapidly used, particularly at 0.03 mg HCN∙L−1 whereas at 0.01 and 0.02 mg HCN∙L−1 the glycogen levels gradually came back to normal after 7–10 d of exposure.

Water Quality Modifies Uptake of Waterborne Methylmercury by Rainbow Trout, Salmo gairdneri

1983 ◽  
Vol 40 (6) ◽  
pp. 824-828 ◽  
Author(s):  
D. W. Rodgers ◽  
F. W. H. Beamish
Keyword(s):  
Water Quality ◽  
Rainbow Trout ◽  
Mercuric Chloride ◽  
Relative Efficiency ◽  
Zinc Sulphate ◽  
Hard Water ◽  
Soft Water ◽  
Salmo Gairdneri ◽  
Calcium Dependent ◽  
Sublethal Concentrations

We measured the efficiency of uptake of waterborne methylmercury relative to oxygen consumption for rainbow trout, Salmo gairdneri, in hard or soft water and during exposure to sublethal concentrations of mercuric chloride or zinc sulphate. The relative efficiency of methylmercury uptake in soft water was more than double that measured in hard water. When mercuric chloride was added with waterborne methylmercury, uptake efficiency was further increased, with similar values obtained in hard and soft water. In contrast, addition of zinc sulphate decreased the relative efficiency of methylmercury uptake. Water quality thus significantly affects the accumulation of waterborne methylmercury by fish. In particular, calcium-dependent changes in gill permeability may explain elevated methylmercury residues observed in fish from lakes of low alkalinity and pH.

Maximum Tolerable Level, Digestion, and Metabolism of D-Glucose (Cerelose) in Rainbow Trout (Salmo gairdneri) Reared on a Practical Trout Diet

1982 ◽  
Vol 39 (9) ◽  
pp. 1229-1234 ◽  
Author(s):  
J. W. Hilton ◽  
J. L. Atkinson ◽  
S. J. Slinger
Keyword(s):  
Rainbow Trout ◽  
Water Temperature ◽  
Glucose Level ◽  
Energy Content ◽  
Liver Glycogen ◽  
Salmo Gairdneri ◽  
Dietary Energy ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Increased Activity ◽  
Tolerable Level

The maximum tolerable dietary level, digestion, and metabolism of D-glucose (cerelose) were investigated in rainbow trout (Salmo gairdneri) reared on practical diets containing optimum protein and lipid levels at two different water temperatures for 12 wk. Liver glycogen levels (LG) and liver:body weight ratios (LB) initially increased with increasing dietary glucose, but leveled off above 10–15% glucose. The plateauing of LB and LG was consistent with the plateauing of liver glucose-6-phosphate dehydrogenase activity (G6PD) and probably overall hexose monophosphate shunt (HMS) activity at high dietary levels of glucose. This indicates that there may be an optimum ratio of digestible carbohydrate to lipid in salmonid diets. LG and LB tended to be higher in trout reared upon the same dietary glucose level in fish reared at 11 °C as compared with those at 15 °C. This may have been caused by increased activity of the HMS as indicated by increased activity of liver G6PD in fish acclimated to 11 °C as compared to trout reared at 15 °C on the same dietary glucose level (when assayed at 15 °C). The digestion coefficient of glucose was uniformly high (96–99%) and not affected by either dietary glucose level (up to 25% of the diet) or water temperature (11 or 15 °C). The maximum tolerable level of glucose in salmonid diets appears to be dependent upon the protein, lipid, and overall energy content of the diet.Key words: trout, glucose digestion, glucose metabolism, maximum tolerable levels, water temperature, dietary energy

CHANGES IN BLOOD GLUCOSE AND LIVER CARBOHYDRATE AFTER INTRAUTERINE INJECTION OF GLUCAGON INTO FOETAL RATS

1969 ◽  
Vol 45 (3) ◽  
pp. 367-374 ◽  
Author(s):  
D. J. S. HUNTER
Keyword(s):  
Blood Glucose ◽  
Liver Glycogen ◽  
Maternal Blood ◽  
Uterine Wall ◽  
Control Group ◽  
Hepatic Glycogen ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Carbohydrate Levels ◽  
Foetal Blood

SUMMARY Maternal blood glucose, foetal blood glucose and liver carbohydrate levels were estimated after foetuses were injected with glucagon through the uterine wall on days 19½, 20½ and 21½ of gestation in the rat. Glucagon had a hyperglycaemic effect in the foetus on all the days studied but the response was greater and more rapid on day 21½ of gestation. Glucagon was shown to decrease liver glycogen on day 20½ and 21½ but again the response was more rapid and more pronounced on day 21½. The normal levels of foetal liver glycogen were similar to those previously found but the normal foetal blood glucose values are lower than previous results. Decrease in liver glycogen observed in the control group of foetuses on day 21½ of gestation together with a loss in foeto-maternal blood glucose relationship on that day of gestation suggest that on day 21½ the foetal rat develops the ability to mobilize hepatic glycogen and thereby to alter its blood glucose level independently from the mother. The significance of the low blood glucose levels found in the foetus is discussed.

scholarly journals The Effect of Intermittent Exercise on Carbohydrate Metabolism in Rainbow Trout, Salmo gairdneri

1966 ◽  
Vol 23 (4) ◽  
pp. 471-485 ◽  
Author(s):  
E. Don Stevens ◽  
Edgar C. Black
Keyword(s):  
Rainbow Trout ◽  
Carbohydrate Metabolism ◽  
Blood Lactate ◽  
Short Duration ◽  
Muscle Glycogen ◽  
Intermittent Exercise ◽  
Liver Glycogen ◽  
Salmo Gairdneri ◽  
Muscle Lactate ◽  
Severe Exercise

The effect of intermittent severe exercise of short duration on carbohydrate metabolism was examined using unanesthetized, intact rainbow trout. The levels of muscle glycogen, muscle lactate, blood lactate, and liver glycogen were determined in fish sampled immediately after severe exercise of 3 sec to 5 min, after recovery of 3 min to 60 min, and after re-exercise of 3 sec to 5 min. It appears that rainbow trout are not well adapted to tolerate frequent exercise of short duration.

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