[Regulation of liver carbohydrate and lipid metabolism by cell volume]

Certain amino acids such as glutamine and proline stimulate liver glycogen synthesis and lipogenesis. This implies cell swelling and leads to the activation of glycogen synthase and acetyl-CoA carboxylase by a common mechanism. This mechanism results from the cell response to swelling and involves a fall in intracellular concentration of chloride ions and an increase in intracellular concentration of glutamate and aspartate. These ions indeed regulate the protein phosphatases that activate glycogen synthase and acetyl-CoA carboxylase.