scholarly journals Ammonia detoxification and localization of urea cycle enzyme activity in embryos of the rainbow trout (Oncorhynchus mykiss) in relation to early tolerance to high environmental ammonia levels

2001 ◽  
Vol 204 (12) ◽  
pp. 2145-2154 ◽  
Author(s):  
Shelby Louise Steele ◽  
Terry David Chadwick ◽  
Patricia Anne Wright
Keyword(s):  
Rainbow Trout ◽  
Amino Acid ◽  
Oncorhynchus Mykiss ◽  
Urea Cycle ◽  
Total Amino Acid ◽  
Cycle Enzyme ◽  
Embryonic Tissues ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Amino Acid Levels ◽  
Urea Cycle Enzyme

SUMMARY The present study investigated the role of ammonia as a trigger for hatching, mechanisms of ammonia detoxification and the localization of urea cycle enzymes in the early life stages of freshwater rainbow trout (Oncorhynchus mykiss). The key urea cycle enzyme carbamoyl phosphate synthetase III was found exclusively in the embryonic body (non-hepatic tissues); related enzymes were distributed between the liver and embryonic body. ‘Eyed-up’ trout embryos were exposed either acutely (2h) to 10mmoll−1 NH4Cl or chronically (4 days) to 0.2mmoll−1 NH4Cl. Time to hatching was not affected by either acute or chronic NH4Cl exposure. Urea levels, but not ammonia levels in the embryonic tissues, were significantly higher than in controls after both acute and chronic NH4Cl exposure, whereas there were no significant changes in urea cycle enzyme activities. Total amino acid levels in the embryonic tissues were unaltered by chronic ammonia exposure, but levels of most individual amino acids and total amino acid levels in the yolk were significantly lower (by 34–58%) than in non-exposed controls. The data indicate that trout embryos have an efficient system to prevent ammonia accumulation in embryonic tissue, by conversion of ammonia to urea in embryonic tissues and through elevation of ammonia levels in the yolk.

Plasma amino acid levels in rainbow trout (Oncorhynchus mykiss)

1995 ◽  
Vol 11 (3-4) ◽  
pp. 309-316 ◽  
Author(s):  
Annette Schuhmacher ◽  
J. Schön ◽  
M. Goldberg ◽  
J. M. Gropp
Keyword(s):  
Rainbow Trout ◽  
Amino Acid ◽  
Oncorhynchus Mykiss ◽  
Plasma Amino Acid ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Amino Acid Levels

scholarly journals Comparative Analysis of Egg Biochemical Composition and Egg Productivity Rainbow Trout (Oncorhynchus mykiss Walbaum, 1792) in Different Stations in Turkey

2021 ◽  
Vol 21 (3) ◽  
pp. 117-127
Author(s):  
Birol Baki ◽  
Dilara Kaya Ozturk ◽  
Serhat Tomgisi
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Rainbow Trout ◽  
Amino Acid ◽  
Oncorhynchus Mykiss ◽  
Egg Quality ◽  
Total Amino Acid ◽  
Human Consumption ◽  
Productivity Analysis ◽  
Rainbow Trout Oncorhynchus Mykiss

In the study, two objectives were selected in determining the quality and efficiency of Oncorhynchus mykiss eggs obtained from different stations: (1) to determine the biochemical, amino and fatty acid composition and egg quality, (2) to study the effect of egg productivity on egg quality. The study was conducted in 5 different production areas which is produces the most rainbow trout eggs in Turkey. Broodstocks over 3 years old were randomly selected from the company. After the egg productivity analysis, biochemical analysis were conducted. The most abundant amino acid in all stations was glutamic acid, followed by leucine, lysine, in that order. Total amino acid and essential amino acid (EAA) values were between 30.40±0.93-44.47±0.43 and 15.69±0.25-23.88±0.07 g/100g, respectively. As a result of analysis of fatty acids, docosahexaenoic acid (DHA), oleic acid and linoleic acid values were higher than other fatty acids. In addition, polyunsaturated (PUFA) values were higher than saturated (SFA) and monounsaturated (MUFA) fatty acid values in the eggs obtained from all stations. Consequently, the amino and fatty acid values of rainbow trout eggs were determined to be sufficient for embryonic development of fish and this values showed rainbow trout eggs as potential source of food for human consumption.

cDNA and amino acid sequences of rainbow trout (Oncorhynchus mykiss) lysozymes and their implications for the evolution of lysozyme and lactalbumin

1991 ◽  
Vol 32 (2) ◽  
pp. 187-198 ◽  
Author(s):  
André Dautigny ◽  
Ellen M. Prager ◽  
Danièle Pham-Dinh ◽  
Jacqueline Jollès ◽  
Farzad Pakdel ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Amino Acid ◽  
Oncorhynchus Mykiss ◽  
Amino Acid Sequences ◽  
Rainbow Trout Oncorhynchus Mykiss

DETERMINATION OF PROTEIN SYNTHESIS IN RAINBOW TROUT, ONCORHYNCHUS MYKISS, USING A STABLE ISOTOPE

1994 ◽  
Vol 189 (1) ◽  
pp. 279-284
Author(s):  
C Carter ◽  
S Owen ◽  
Z He ◽  
P Watt ◽  
C Scrimgeour ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Rainbow Trout ◽  
Amino Acid ◽  
Oncorhynchus Mykiss ◽  
Considerable Proportion ◽  
Published Data ◽  
Short Term ◽  
Terrestrial Mammals ◽  
Rainbow Trout Oncorhynchus Mykiss

It has been suggested (Houlihan, 1991) that the consumption of 1 g of protein in a variety of species of fish stimulates the synthesis of, approximately, an equal amount of protein. Although synthesis of protein may account for as much as 40 % of the whole-animal oxygen consumption (Lyndon et al. 1992), only about 30 % of the synthesized proteins are retained as growth (Houlihan et al. 1988; Carter et al. 1993a,b). Thus, one focus of attention is the potential advantage gained by fish in allocating a considerable proportion of assimilated energy to protein turnover in contrast to relatively low-cost, low-turnover protein growth (Houlihan et al. 1993). Rates of protein synthesis in several species of fish have been measured using radioactively labelled amino acids, frequently given as a flooding dose (reviewed by Fauconneau, 1985; Houlihan, 1991). These measurements cannot be made for longer than a few hours because of the decline in specific radioactivity in the amino acid free pool. However, as protein synthesis rates vary during the course of a day as a result of the post-prandial stimulation, and since radiolabelled amino acid methodology is invasive, short-term and terminal, it has been difficult to be certain of the relationship between protein growth measured in the long term and protein synthesis rates measured in the short term. This paper addresses these problems by developing a method using 15N in orally administered protein to measure protein synthesis rates in fish over relatively long periods, the aim being to use procedures that are as non-invasive and repeatable as possible. The use of stable isotopes to measure protein metabolism is well established in terrestrial mammals (see Rennie et al. 1991; Wolfe, 1992), but to our knowledge the only published data for aquatic ectotherms are on the blue mussel (Mytilus edulis L.) (Hawkins, 1985). In the present study, rates of protein synthesis of individual rainbow trout [Oncorhynchus mykiss (Walbaum)] were calculated from the enrichment of excreted ammonia with 15N over the 48 h following the feeding of a single meal (dose) containing protein uniformly labelled with 15N by use of an end-point stochastic model (Waterlow et al. 1978; Wolfe, 1992). Application of this type of modelling would appear to be ideal for measuring ammonotelic fish nitrogen metabolism since, unlike the situation in mammals, the catabolic flux of amino acids through urea is very small. Further, ammonia is excreted directly into the surrounding water via the gills and is not stored for any length of time, in contrast to the situation in mammals, so the rate of tracer appearance is easily measurable.

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