Ketone body utilization in duodenum. Differential effect of fasting on lipogenesis from acetoacetate and 3-hydroxybutyrate.

The effect of fasting and refeeding on oxidation, lipogenesis and amino acid synthesis from ketone bodies has been studied in neonatal chick duodenal mucosa. Oxidation and amino acid synthesis were higher from acetoacetate and were stimulated by fasting from both 3-hydroxybutyrate and acetoacetate. On the contrary, lipogenesis was always higher from 3-hydroxybutyrate and fasting reduced lipogenesis rate from acetoacetate (by 66%) but not from 3-hydroxybutyrate. Results suggests the existence of a cytosolic fast-dependent acetoacetyl-CoA synthetase in chick duodenal mucosa which is involved in phospholipid synthesis.