The Sound of Evolution
Levothyroxine
Mechanism of action:
Levothyroxine is a synthetic thyroxine preparation and is the artificial form of T4 (tetraiodothyronine). After entering the body, levothyroxine (T4) is converted into triiodothyronine (T3) by deiodinases in the liver, kidneys, and peripheral tissues, with T3 serving as the principal active form. T3 binds to thyroid hormone receptors in the cell nucleus and regulates transcription of multiple genes, thereby influencing basal metabolic rate, protein, lipid, and carbohydrate metabolism, cardiac contractility and heart rate, and central nervous system and skeletal development.
Reference(s):
1. Uchino H et al. (2002). Transport of amino acid-related compounds mediated by L-type amino acid transporter 1 (LAT1): insights into the mechanisms of substrate recognition. Mol Pharmacol.
2. Cheng SY et al. (2010). Molecular aspects of thyroid hormone actions. Endocr Rev.
3. Chon DA et al. (2018). Concurrent Milk Ingestion Decreases Absorption of Levothyroxine. Thyroid.