Liver insulin-like growth factor-I mRNA is not affected by diet composition or ration size but shows diurnal variations in regularly-fed gilthead sea bream (Sparus aurata).
Nutritional regulation of insulin-like growth factor-I (IGF-I) mRNA was assessed in liver of gilthead sea bream (Sparus aurata). As in mammals, starvation lowered the IGF-I mRNA content, which was recovered by refeeding. However, in contrast to previous observations in rats, neither diet composition nor ration size significantly affected hepatic IGF-I mRNA. Although fish growth depended on the quantity of diet supplied, no relationship was found between growth and liver IGF-I mRNA levels, a fact that challenges the importance, at least in fish, of liver-derived IGF-I on body growth attributed by the classical somatomedin hypothesis. In addition, diurnal modulation of mRNA levels occurred following food intake, suggesting that the intake of food may play a key role in the regulation of the short-term anabolic effects of IGF-I.
Metón
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Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia,Universitat de Barcelona, 08028 Barcelona, Spain.
Caseras
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Cantó
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Fernández
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Baanante
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D000818:Animals; D002940:Circadian Rhythm; D004032:Diet; D004435:Eating / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D008099:Liver / Q000378:metabolism*; D010473:Perciformes / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism*; D013217:Starvation / Q000378:metabolism
D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I