Brain serotonin and the control of food intake in rainbow trout ( Oncorhynchus mykiss ): effects of changes in plasma glucose levels

2002 ◽  
Vol 188 (6) ◽  
pp. 479-484 ◽  
Author(s):  
Ruibal C. ◽  
Soengas J. ◽  
Aldegunde M.
Keyword(s):  
Rainbow Trout ◽  
Food Intake ◽  
Oncorhynchus Mykiss ◽  
Plasma Glucose ◽  
Brain Serotonin ◽  
Glucose Levels ◽  
Rainbow Trout Oncorhynchus Mykiss

scholarly journals FEEDING RANK AND BRAIN SEROTONERGIC ACTIVITY IN RAINBOW TROUT ONCORHYNCHUS MYKISS

1993 ◽  
Vol 179 (1) ◽  
pp. 197-211
Author(s):  
S. Winberg ◽  
C. G. Carter ◽  
I. D. Mccarthy ◽  
Z. Y. He ◽  
G. E. Nilsson ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Food Intake ◽  
Oncorhynchus Mykiss ◽  
Social Rank ◽  
Growth Stress ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Serotonergic Activity ◽  
The Status ◽  
Average Share ◽  
Hydroxyindoleacetic Acid

Two methods for assessing the status of an individual rainbow trout Oncorhynchus mykiss within a group hierarchy, radiographic determination of individual food intake and analysis of brain serotonergic activity, were compared. The results showed that individual food intake, measured as the average share of the group meal, and brain serotonergic activity, measured as brain levels of 5- hydroxyindoleacetic acid (5-HIAA) or as 5-HIAA/5-HT (serotonin) ratios, were inversely correlated with each other, suggesting that both methods could be used as indicators of the position of the rainbow trout in a dominance hierarchy. In addition, specific growth rate correlated significantly with brain 5-HIAA/5-HT ratios. The results indicate that the increase in brain 5-HIAA/5-HT ratios in subordinate individuals is caused by an increased use (release) of 5-HT in these fish, and not by an increase in the level of tryptophan, the amino acid precursor of 5-HT. The relationships between social rank, food intake, growth, stress and brain serotonergic activity of fish in a social hierarchy are discussed.

Effects of feeding on waterborne silver uptake and depuration in rainbow trout (Oncorhynchus mykiss)

2002 ◽  
Vol 59 (2) ◽  
pp. 350-360 ◽  
Author(s):  
Barbara OB Bertram ◽  
Richard C Playle
Keyword(s):  
Body Weight ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Plasma Glucose ◽  
Elimination Rate ◽  
External Factors ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Depuration Period ◽  
Free Ion ◽  
Subsequent Elimination

Rainbow trout (Oncorhynchus mykiss, ~50 g) were exposed to 0.1 µM AgNO3 in ion-poor water (Ca ~300 µM, pH ~7, 13°C) with or without being fed 2% of their body weight daily. Gills, plasma, livers, and bile were sampled after 4 h, 24 h, and 1 week. Feeding did not alter Ag uptake by trout, and did not prevent decreases in plasma Na and Cl caused by Ag. To study Ag depuration, trout were exposed to 0.1 µM AgNO3 for one week and then were placed in Ag-free, ion-poor water with or without being fed 1% of their body weight daily. Plasma Ag decreased over the 15-day depuration period (elimination rate, ke = 0.085 day–1), but there were no effects of feeding on Ag depuration. There were no physiological differences between fed and unfed fish except for slightly higher plasma glucose concentrations and higher condition factors in fed fish by the end of the Ag depuration period. Thus, once Ag has entered a fish, subsequent elimination (e.g., from the plasma) is not affected by food-related processes such as biliary excretion or increased metabolic rate, or by external factors like food debris in the water.

Macronutrient-induced differences in food intake relate with hepatic oxidative metabolism and hypothalamic regulatory neuropeptides in rainbow trout (Oncorhynchus mykiss)

2012 ◽  
Vol 106 (4) ◽  
pp. 499-505 ◽  
Author(s):  
A. Cláudia Figueiredo-Silva ◽  
Subramanian Saravanan ◽  
Johan W. Schrama ◽  
Sadasivam Kaushik ◽  
Inge Geurden
Keyword(s):  
Rainbow Trout ◽  
Food Intake ◽  
Oncorhynchus Mykiss ◽  
Oxidative Metabolism ◽  
Rainbow Trout Oncorhynchus Mykiss
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