Suppression of fatty acids synthesis in brown adipose tissue of mice fed diets rich dm long chain fatty acids

The influence of dietary lipid on fatty acid synthesis in brown adipose tissue has been investigated by feeding different high-fat diets to cold-acclimated mice for a period of 2 weeks. Fatty acid synthesis was measured in vivo with ³H₂O, and the fats used in the study were maize oil, beef tallow and medium chain triacylglycerol oil. In the mice fed the maize oil and the beef tallow diets fatty acid synthesis was inhibited in all tissues examined - inter-scapular brown adipose tissue, epididymal white adipose tissue, the liver and the carcass. Synthesis was more inhibited, however, in brown adipose tissue than in other tissues, and the inhibition was greater on the maize oil diet than on the beef tallow. The medium chain triacylglycerol oil had no inhibitory effect on fatty acid synthesis in any tissue, and hepatic synthesis was even elevated on this diet. It is concluded that fatty acid synthesis in brown adipose tissue, as in other lipogenic tissues, is subject to strong suppression by dietary long chain fatty acids, and particularly by linoleic acid.