Regulation of lipid metabolism in chicken liver by dietary cereals.

The activities of acetyl-CoA carboxylase (EC 6.4.1.2), fatty acid synthetase (FAS) and beta-hydroxy-beta-methylglutaryl-CoA (HMG-CoA) reductase (EC 1.1.1.88) were determined in subcellular fractions of livers from chicks fed different cereal-based diets. With a barley-based diet as compared to corn, the following was observed: body and liver weights decreased 31%; HMG-CoA reductase activity of liver decreased 79%; acetyl-CoA carboxylase activity increased 3-fold; fatty acid synthesis increased 5-fold, and plasma and liver cholesterol decreased 45% and 35%, respectively. The suppression and induction of activities of the two divergent pathways (cholesterol and fatty acid biosynthesis) persisted for at least 21 days. Wheat, oats and rye showed a similar but less pronounced effect. The pronounced decrease in plasma cholesterol level and HMG-CoA reductase activity have implications for human nutrition and possible control of the cardiovascular diseases in which cholesterol plays a key role.