| Popis: |
Individuals are more or less prone to excessive fat deposits and body weight. This could result from differences in the expression of gene involved in adipose tissue metabolism in early life. This study aimed to identify such possible differences in puppy dogs. Twenty-four 4-wk old females Beagle puppies were raised in the same environment, and fed with the same diet, ad libitum but for 3.5 h. Dogs were allotted in 3 groups according to their fat-free mass, fat mass, and pelvic circumference at 24 months of age: IW (n = 9; ideal body condition, OW1 (n = 6; moderately overfat) and OW2 (n = 9; overfat/obese). Subcutaneous and visceral adipose tissue (VAT) samples were collected at the time when animals were neutered (8 months). The mRNA level of genes involved in the regulation of lipolysis (perilipin, HSL), lipogenesis (ACC, ADRP, CPT1, FAS, FABP), adipogenesis (PPARg, SREBP-1c), thermogenesis (UCP1, UCP2), glucose uptake (GLUT4), insulin signaling (IRS2), and adiponectin production was assessed by real time RT-PCR. Gene expression levels in the three groups were compared by a Wilcoxon test. Ethics approval was granted by the French Ministry of Research and Royal Canin’s Ethical Committee. Compared to IW, OW2 dogs had a lower expression of UCP1 in the VAT (P = 0.049). This could result in reduced heat production by non-shivering thermogenesis. Moreover, a low UCP1 expression has been linked to obesity. Compared to IW, OW1 dogs had a higher transcription level of ACC and ADRP genes (P < 0.05). ACC is a point of regulation of the FA synthesis whereas ADRP is involved in the differentiation of the pre-adipocytes, and fat storage. These results suggest that the overweight/obesity phenotype could be associated with a lower heat loss, and the moderately overweight phenotype with a higher ability to fat synthesis compared to the lean phenotype. |
