Data/hora: 01/06/2024 11:54:29

Provedor de dados: | 5
País: | France
Título: | Regulation of the somatotropic axis by dietary factors in rainbow trout (Oncorhynchus mykiss)
Autores: | Gomez Requeni, P; Calduch Giner, J; De Celis, S; Medale, Francoise; Kaushik, Sadasivam; Perez Sanchez, J.
Data: | 2005-09
Ano: | 2005
Palavras-chave: | Insulin like growth factor; Growth hormone receptor; Growth hormone; Plant proteins; Rainbow trout.
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.
Tipo: | Text
Idioma: | Inglês

Identificador:

http://archimer.ifremer.fr/doc/2005/publication-3620.pdf

DOI:10.1079/BJN20051521

Editor: | Cambridge University Press
Relação: | http://archimer.ifremer.fr/doc/00000/3620/
Formato: | application/pdf
Fonte: | British Journal of Nutrition (0007-1145) (Cambridge University Press), 2005-09 , Vol. 94 , N. 3 , P. 353-361
Fonte: | The Authors 2005. Cambridge