| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
Regulation of the somatotropic axis by dietary factors in rainbow trout (Oncorhynchus mykiss)
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| Autores: |
Gomez Requeni, P
Calduch Giner, J
De Celis, S
Medale, Francoise
Kaushik, Sadasivam
Perez Sanchez, J
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| Data: |
2005-09
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| Ano: |
2005
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| Palavras-chave: |
Insulin like growth factor
Growth hormone receptor
Growth hormone
Plant proteins
Rainbow trout
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| Resumo: |
The activity of the somatotropic axis was analysed in juvenile rainbow trout (Oncorhynchus mykiss) fed either a fishmeal-based diet (FM) or graded levels of plant proteins to replace 50 % (PP50 diet), 75 % (PP75 diet) or 100 % (PP100 diet) of the fishmeal protein. For this purpose, partial cloning and sequencing of the gene encoding rainbow trout growth hormone receptor (GHR) was first accomplished by RT-PCR, using degenerate primers based on the sequences of non-salmonid fish GHR. Growth rates and energy retention were lowered by the PP75 and PP100 diets and a concurrent and progressive increase in plasma levels of growth hormone (GH) was found. However, no changes in hepatic GH binding and total plasma insulin-like growth factor (IGF)-I levels were observed among the four experimental groups. This fact agrees with the lack of changes in hepatic measurements of GHR and IGF-I transcripts. No consistent changes in IGF transcripts were found in peri-visceral adipose tissue and skeletal muscle, but GHR mRNA was up-regulated in the peri-visceral adipose tissue of fish fed the PP75 and PP100 diets, which would favour the lipolytic action of GH. Two specific bands (47 and 33 kDa) of IGF-binding proteins were found in the plasma of all analysed fish, but the sum of the two integrated areas increased progressively with plant protein supply, which might reflect a reduced free IGF availability. Therefore, in our experimental model, the growth impairment could be due, at least in part, to a lowered availability of biologically active IGF (free IGF fraction) rather than to liver GH desensitization or defect in IGF synthesis and release at the systemic and/or paracrine-autocrine level.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
http://archimer.ifremer.fr/doc/2005/publication-3620.pdf
DOI:10.1079/BJN20051521
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| Editor: |
Cambridge University Press
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| Relação: |
http://archimer.ifremer.fr/doc/00000/3620/
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| Formato: |
application/pdf
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| Fonte: |
British Journal of Nutrition (0007-1145) (Cambridge University Press), 2005-09 , Vol. 94 , N. 3 , P. 353-361
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| Direitos: |
The Authors 2005. Cambridge
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