BIOL 2020 Lecture Notes - Lecture 22: Biliary Tract, Bile Acid, Surrogate Endpoint
8 May 2020
School
Department
Course
Professor
Document Summary
We will zoom in on the hepatocyte area. And then we will zoom out and look at how bilirubin is transported and handled in the body. Bilirubin is a breakdown product of heme catabolism. Also, cytochoromes have a heme moiety within them. And, the resulting catabolic product (bilirubin) is not very water soluble. It might look water soluble (hydroxyl groups), so you would think it would interact well in hydrophilic environment. But these hydrogens bind intramolecularly with one another, so they can"t bind water ohs. The unconjugated bilirubin is transported via albumin to hepatocyte. Hepatocyte takes up bilirubin that has been bound to albumin. The liver cell then conjugates bilirubin with two glucoronic acids. Once bilirubin is conjugated, it is secreted into the canaliculus, the smallest of the ductules in the biliary tract. Since the flow is form blood, to hepatocyte to canaliculus we consider the biliary tract to be distal to the hepatocyte.
