Acute induction of uncoupling protein 1 by citrulline in cultured explants of white adipose tissue from lean and high-fat-diet-fed rats

International audience; A diet enriched with citrulline (CIT) reduces white adipose tissue (WAT) mass. We recently showed that CITstimulated β-oxidation in rat WAT explants from young (2–4 months) but not old (25 months) rats. Here we show thatboth in old rats and high-fat-diet-fed young rats, uncoupling protein one (UCP1) mRNA and protein expressions wereweaker than those in young control rats. Selectively in WAT from young rats, a 24h CIT treatment up-regulatedexpressions of UCP1, peroxisome proliferator-activated receptor-x (PPARx/, PPARy-coactivator-1-x and mitochondrialtranscription-factor-A whereas it down-regulated PPARy gene expression, whatever the diet. These results suggestthat CIT induces a new metabolic status in WAT, with increased β-oxidation and uncoupling of respiratory chain,resulting in energy expenditure that favors fat mass reduction.