PHAR 303 Lecture Notes - Lecture 13: Hepatotoxicity, Lobules Of Liver, Portal Vein
23 Mar 2016
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Document Summary
Interface between digestive system & blood: ~70% blood comes from the portal vein: from stomach and intestines -- oxygen-poor/nutrient-rich, ~30% blood comes from hepatic artery -- oxygen-rich. Reservoir of microsomal and cytosolic phases i & ii xenobiotic-metabolizing enzymes. Metabolism of chemicals can lead to inactivation or conversion into toxic metabolites. One single exposure of a toxicant can lead to multiple exposures to the liver. The drug goes to the liver through the portal vein where it is metabolized, is secreted in the bile, and goes back to the gut which contains bacterial flora which will de-conjugate the drug. The free toxicant can then go back to the liver. Lobules are made from hepatocyte plates or lines. In the middle of the lobule there is the central vein and at each angle of the lobule is the portal triad made up of the vein and bile duct.
