Liver and Integration of Metabolism Flashcards
What is the purpose of metabolism of drugs and xenobiotics?
What are the 2 phases and what happens?
TO make them HYDROPHILIC
Phase 1: cytochrome enzyme complex of NADPH-cutochrome P450
- involve the introduction of OH or COOH groups through OXIDATION of parent compound
Phase 2: products are CONJUGATED with compounds (glucoronic acid, glycine, taurine, sulfate) to make them HYDROPHILIC
How is Vitamin A: Retinol transported to the liver? In which form- esterified or not esterified?
- As an ESTER OF LONG CHAIN FATTY ACIDS
- in CHYLOMICRONS
When does the liver mobilize vitamin A?
It mobilizes the vitamin by hydrolyzing _____.
This then binds to ______ and is secreted in the blood.
When Vitamin A is LOW it mobilizes the vitamin by hydrolyzing retinal ester
- Retinol Binding Protein (RBP)
In order to be secreted into the blood, what does Retinol require?
Retinol Binding Protein
How is Vitamin D3 transported? In which form (esterified or non esterified)?
Transported in chylomicrons in the NON -ESTERIFIED form
Where are vitamin D stores found? (2)
- Adipose tissues
2. Skeletal muscle
What organ is responsible for the activation of D3?
What is it converted to?
What is the active form of D? Where does this get converted again?
- LIVER
- Converted to 25 - Hydroxycholecalciferol (STORAGE FORM)
- 1,25-OH-D3 –> in the KIDNEY
The liver synthesizes ___ for Vitamin D.
The vitamin D binding protein
What is a major source of vitamin K?
Why is vitamin K necessary?
- SKELETAL MUSCLE
2. Presence is required in he hepatocyte for synthesis of prothrombin (the precursor to thrombin - the clotting factor)
80% of copper is excreted in ______.
Bile caniliculi
What are 3 ways that the liver can modify or amplify hormone action?
- D3 –> conversion to 25-hydroxycholecalciferol
- Thyroid hormones: T4 to 3
- synthesis of IGF
