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Metabolic adaptations of rats fed diets with different concentrations of proteín exposed to a cold temperature
Author(s) -
FloresGalicia Isabel,
Castro Ana Laura,
TorreVillalvazo Ivan,
PalaciosGonzalez Berenice,
LopezRomero Patricia,
Torres Nimbe,
Aleman Gabriela,
Tovar Armando R
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.983.21
Subject(s) - thermogenesis , brown adipose tissue , gluconeogenesis , medicine , endocrinology , beta oxidation , casein , catabolism , amino acid , protein turnover , chemistry , white adipose tissue , phosphoenolpyruvate carboxykinase , fatty acid , enzyme , biochemistry , biology , metabolism , adipose tissue , protein biosynthesis
The use of energy substrates under different environmental conditions change according to the physiological needs of the body. Exposure to a cold temperature stimulates the use of fatty acid for thermogenesis. However, there is scarce evidence about the molecular adaptations that occur when animals are exposed to 4°C and short term fed with different concentrations of dietary protein. The aim of this work was to study the effect of 12 hr exposure to a 4°C on the expression of genes of amino acid catabolism, gluconeogenesis, and fatty oxidation in liver, brown (B) and white (W) adipose tissue (AT) of rats fed a 6, 20 or 50% casein diets. Expression of the amino acid degrading enzymes SDH, HAL, TAT and TDO in liver increased as the amount of dietary protein increased. Similarly, Hepatic PEPCK expression increased as the amount of dietary protein increased. Interestingly, PEPCK expression also increased in BAT as dietary protein increased, and it was accompanied with an increase in the phosphorylation state of AMPK and ACC. PGC1α and UCP‐1 increased independently of the amount of protein in the diet. These results suggest that amino acid surplus is oxidized in the liver, possibly sparing fatty acids that are actively esterified in BAT due to an elevated rate of glyceroneogenesis in BAT to maintain a high level of substrate for thermogenesis. Supported by CONACYT Grant No. 41799‐M.