Endocrine control of oleic acid and glucose metabolism in rainbow trout (Oncorhynchus mykiss) muscle cells in culture.
Am J Physiol Regul Integr Comp Physiol
; 299(2): R562-72, 2010 Aug.
Article
em En
| MEDLINE
| ID: mdl-20484701
ABSTRACT
The effects of insulin and IGF-I on fatty acid (FA) and glucose metabolism were examined using oleic acid or glucose as tracers in differentiated rainbow trout (Oncorhynchus mykiss) myotubes. Insulin and IGF-I significantly reduced the production of CO(2) from oleic acid with respect to the control values. IGF-I also significantly reduced the production of acid-soluble products (ASP) and the concentration of FA in the medium, while cellular triacylglycerols (TAG) tended to increase. Only insulin produced a significant accumulation of glycogen inside the cells in glucose distribution experiments. Incubation with catecholamines did not affect oleic acid metabolism. Cells treated with rapamycin [a target of rapamycin (TOR) inhibitor] significantly increased the oxidation of oleic acid to CO(2) and ASP, while the accumulation of TAG diminished. Rosiglitazone (a peroxisome proliferator-activated receptor gamma agonist) and etomoxir (a CPT-1 inhibitor) produced a severe and significant reduction in the production of CO(2) and ASP. Rosiglitazone and etomoxir also produced a significant accumulation of FA outside and inside the cells, respectively. No significant effects of these drugs on glucose distribution were observed. These data indicate that insulin and IGF-I act as anabolic hormones in trout myotubes in both oleic acid and glucose metabolism, although glucose oxidation appears to be less sensitive than FA oxidation to insulin and IGF-I. The use of rapamycin, etomoxir, and rosiglitazone may help us to understand the mechanisms of regulation of lipid metabolism in fish.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fator de Crescimento Insulin-Like I
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Oncorhynchus mykiss
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Fibras Musculares Esqueléticas
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Ácido Oleico
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Metabolismo Energético
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Glucose
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Insulina
Limite:
Animals
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article