The liver metabolizes estrogen through a two-phase process.
Liver's Role in Estrogen Metabolism
The liver plays a crucial role in processing estrogen, primarily to prepare it for excretion from the body. Here's how it works:
Phase I: Hydroxylation
- In the first phase of estrogen metabolism, the liver performs hydroxylation.
- This process involves adding a hydroxyl (-OH) group to the estrogen molecule.
- This initial step modifies the estrogen, preparing it for the next phase.
Phase II: Conjugation
- Following hydroxylation, the liver undertakes Phase II metabolism, which involves conjugation.
- This phase encompasses three primary reactions:
- Methylation: Adding a methyl group (-CH3) to the estrogen molecule.
- Sulfation: Attaching a sulfate group (-SO4) to the estrogen molecule.
- Glucuronidation: Binding a glucuronic acid molecule to the estrogen.
- These conjugation processes make the estrogens more water-soluble. This increased solubility facilitates their excretion via the kidneys and bile.
- The reference confirms, "Estrogens are metabolized in the liver in two main phases: Phase I (hydroxylation) and Phase II (methylation, sulfation, and glucuronidation)".
Types of Estrogens
It is worth noting that not all estrogens are created equal. According to the provided reference:
- Estradiol and estrone are the most active forms of estrogen.
- Estriol is a weaker estrogen, produced as a byproduct of estrone.
Summary
In summary, the liver metabolizes estrogens through a two-step process involving Phase I (hydroxylation) and Phase II (methylation, sulfation, and glucuronidation). These metabolic processes prepare the estrogens for elimination from the body.
