The Metabolism of Drugs and Xenobiotics ■ Energy Metabolism in the Liver ■ Protein and Amino Acid Metabolism in the Liver

1. The liver sinusoid is lined with sinusoidal cells (endothelial cells), Kupffer cells, and fat storage cells (also called stellate or Ito cells), which perform important metabolic functions and defend the liver. 2. The liver plays an important role in maintaining blood glucose levels and in metabolizing drugs and toxic substances. 3. The liver has a remarkable capacity to regenerate. 4. The liver is extremely important in maintaining an adequate supply of nutrients for metabolism. 5. The liver synthesizes glucose from noncarbohydrate sources, a process called gluconeogenesis. 6. The liver is the first organ to experience and respond to changes in plasma insulin levels. 7. The liver is one of the main organs involved in fatty acid synthesis. 8. The liver aids in the elimination of cholesterol from the body. 9. The liver is a storage area for fat-soluble vitamins and iron. 10. The liver modifies the action of hormones released by other organs. K E Y C O N C E P T S