Beschreibung:
<jats:p>Glutamate (Glu) is the most abundant amino acid (AA) in foods. Our previous study has shown that removal of Glu from diet increased body fat mass and hepatic triglyceride. This study investigated the underlying mechanism of the fat increase caused by Glu‐free diet. Male SD rats of 3 weeks old were fed fixed amount of diets containing either balanced AA mixture (4% Glu), Glu‐free mixture or low AA mixture (isonitrogenous to the Glu‐free). Fat oxidation was estimated by monitoring <jats:sup>13</jats:sup>CO<jats:sub>2</jats:sub> in the exhaled gas after ingestion of experimental diets containing [1,1,1‐<jats:sup>13</jats:sup>C<jats:sub>3</jats:sub>]tripalmitin. <jats:italic>De novo</jats:italic> lipogenesis was estimated from deuterium incorporation of given D<jats:sub>2</jats:sub>O into hepatic fatty acids. Feeding of Glu‐free diet suppressed the oxidation of dietary tripalmitin but promoted <jats:italic>de novo</jats:italic> lipogenesis in the liver. The mRNA expression involved in fatty acid synthesis (FAS and Elovl6) was also up‐regulated. Three weeks ingestion of Glu‐free diet resulted in remarkable increase in contents of fatty acids such as palmitate, stearate and oleate in hepatic triglyceride. These findings suggest that dietary Glu has the inhibitory effect on fat accumulation by both enhancement of fat oxidation and suppression of <jats:italic>de novo</jats:italic> lipogenesis.</jats:p>