Entity

Time filter

Source Type


Joffin N.,University of Paris Descartes | Joffin N.,Institute National Of La Sante Et Of La Recherche Medicale Umr S 1124 | Jaubert A..-M.,Institute National Of La Sante Et Of La Recherche Medicale Umr S 1124 | Jaubert A..-M.,University of Versailles | And 16 more authors.
Molecular Nutrition and Food Research | Year: 2014

Scope: High-fat diet (HFD) increases visceral adipose tissue (AT). Our aim was to evaluate whether citrulline (CIT) affected nonesterified fatty acid (NEFA) metabolism in AT from HFD-fed rats. Methods and results: Rats were fed for 8 weeks with either a control diet (CD) or HFD. Retroperitoneal AT explants were exposed to 2.5 mmol/L CIT for 24 h. We analyzed lipolysis, beta-oxidation, glyceroneogenesis, and the expression of the key associated enzymes. CIT doubled NEFA release selectively in HFD AT. Phosphorylation of hormone-sensitive lipase was upregulated 50 and 100% by CIT in CD and HFD AT, respectively. Under CIT, beta-oxidation increased similarly whatever the diet, whereas glyceroneogenesis, which permits NEFA re-esterification, was downregulated 50 and 80% in CD and HFD AT, respectively. In the latter, the important decrease in re-esterification probably explains the rise of NEFA release. A pretreatment with the nitric oxide synthase inhibitor N ω-nitro-l-arginine methyl ester abolished CIT effects. Conclusion: These results demonstrate direct lipolytic and antiglyceroneogenic effects of CIT on CD and HFD AT. The selective CIT-mediated NEFA release from HFD AT was probably the consequence of the drastic decrease in glyceroneogenesis and nitric oxide was a mediator of CIT effects. These results provide evidence for a direct action of CIT on AT to reduce overweight. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Joffin N.,University of Paris Descartes | Joffin N.,Institute National Of La Sante Et Of La Recherche Medicale Umr S 1124 | Jaubert A..-M.,Institute National Of La Sante Et Of La Recherche Medicale Umr S 1124 | Jaubert A..-M.,University of Versailles | And 14 more authors.
Molecular Nutrition and Food Research | Year: 2014

Scope: During aging, increased visceral adipose tissue (AT) mass may result in impaired metabolic status. A citrulline (CIT)-supplemented diet reduces AT mass in old rats. We hypothesized that CIT could directly affect fatty acid (FA) metabolism in retroperitoneal AT. Methods and results: A 24-h exposure of AT explants from old (25 months) rats to 2.5 mM CIT induced a 50% rise in glycerol and FA release, which was not observed in explants from young (2 months) animals. The phosphorylated form of hormone-sensitive lipase, a key lipolytic enzyme, was 1.5-fold higher in CIT-treated explants from old and young rats, whereas glyceroneogenesis, that provides glycerol-3P requested for FA re-esterification, and its key enzyme phosphoenolpyruvate carboxykinase, were down-regulated 40-70%. Specifically in young rats, beta-oxidation capacity and gene expressions of carnitine palmitoyl transferase 1-b and very long chain acyl-CoA dehydrogenase were strongly up-regulated by CIT. In contrast, in old rats, while glyceroneogenesis was lower, beta-oxidation was not affected, enabling increased FA release. Conclusion: Hence, in visceral AT, CIT exerts a specific induction of the beta-oxidation capacity in young rats and a selective stimulation of FA release in old rats, therefore providing a direct mechanism of CIT action to reduce AT mass. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Discover hidden collaborations