Format

Send to

Choose Destination
Domest Anim Endocrinol. 2010 Jul;39(1):26-33. doi: 10.1016/j.domaniend.2010.01.003. Epub 2010 Feb 2.

Molecular regulation of lipid metabolism in liver and muscle of rainbow trout subjected to acute and chronic insulin treatments.

Author information

1
INRA, UMR1067 Nutrition Aquaculture et Génomique, Saint-Pée-sur-Nivelle, France. spolakof@st-pee.inra.fr <spolakof@st-pee.inra.fr>

Abstract

Although the metabolic actions of insulin in fish have been investigated widely in the past several years, lipid metabolism has received little attention, especially in tissues like the liver or white muscle. In the present study, rainbow trout received insulin treatments both acutely (intraperitoneal injection) and chronically (through mino-osmotic pumps) to elucidate hormone metabolic actions at molecular levels on the 2 main insulin target tissues in trout, namely, liver and muscle. Plasma and free fatty acid concentrations in plasma, as well as mRNA measurements of some key enzymes involved in lipid metabolism, were assessed in these tissues after 6h and 4 d of acute and chronic insulin treatments, respectively. Our results showed that although fish received the same final total amount of hormone in both treatments, the actions of insulin on lipid metabolism were both time and tissue dependent. After the acute insulin treatment, the main anabolic role of insulin was reflected in decreased plasma free fatty acid concentrations linked to enhanced hepatic lipogenesis. We also found that insulin increased the mRNA levels of enzymes involved in lipid oxidation, perhaps to counteract insulin-induced hypoglycemia. In contrast, our data show that after chronic insulin treatment, liver and muscle exhibit different metabolic strategies: whereas in the liver chronic insulin-induced hypoglycemia may stimulate lipolytic processes to spare glucose stores, the muscle responds directly to the anabolic hormone action by increasing its lipogenic capacity and by inhibiting pathways of lipid oxidation.

PMID:
20181454
DOI:
10.1016/j.domaniend.2010.01.003
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center