title: Coordinate suppression of liver acetyl-CoA carboxylase and fatty acid synthetase by polyunsaturated fat.
abstract: Polyunsaturated fats (PUFA) suppressed hepatic fatty acid synthesis and the activities of lipogenic enzymes more effectively than did saturated fats. The activity of glycolytic enzymes--glucokinase, phosphofructokinase and pyruvate kinase--were not affected by PUFA. The absolute rate of liver fatty acid synthesis after meal ingestion was very similar to the maximal activities of acetyl-CoA carboxylase and fatty acid synthetase. When PUFA was supplemented to a fat-free diet, the activities of carboxylase and synthetase decreased similarly over 3 days. During the 3 days, the concentration of liver malonyl-CoA (after meal ingestion) did not significantly differ between the fat-free and PUFA dietary treatments. Apparently PUFA feeding caused a coordinate decrease in the utilization and production of malonyl-CoA which resulted in no net change in malonyl-CoA pool size. Thus the mechanism by which PUFA suppresses fatty acid synthesis appears to be by coordinately and specifically reducing the amount of carboxylase and fatty acid synthetase.
mesh_terms: D000103:Acetyl-CoA Carboxylase / Q000378:metabolism*; D000818:Animals; D004040:Dietary Carbohydrates / Q000494:pharmacology; D004041:Dietary Fats / Q000494:pharmacology*; D064429:Fatty Acid Synthases / Q000378:metabolism; D005227:Fatty Acids / Q000096:biosynthesis*; D005941:Glucokinase / Q000378:metabolism; D008025:Ligases / Q000378:metabolism*; D008055:Lipids / Q000096:biosynthesis; D008099:Liver / Q000201:enzymology*; D008297:Male; D010732:Phosphofructokinase-1 / Q000378:metabolism; D011770:Pyruvate Kinase / Q000378:metabolism; D051381:Rats; D012450:Safflower Oil / Q000494:pharmacology
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005227:Fatty Acids; D008055:Lipids; D012450:Safflower Oil; D064429:Fatty Acid Synthases; D010732:Phosphofructokinase-1; D005941:Glucokinase; D011770:Pyruvate Kinase; D008025:Ligases; D000103:Acetyl-CoA Carboxylase