MECHANISM OF HORMONE ACTION
- Hormones bind to specific proteins (hormone receptors) in the target tissues and produce effect on them.
- There are two types of receptors: membrane bound receptors (hormone receptors present on the cell membrane of the target cell) and intracellular receptors (receptors present inside the target cell).
- Hormone-receptor complex is formed on binding of hormone to the receptor.
- Receptors are specific.
- This complex leads to certain biochemical changes in the target tissue.
- Types of hormones:
- Peptide, polypeptide, protein hormone
- Amino-acid derivatives
Hormones that interact with membrane-bound receptors generate second messenger (do not enter the target cell). These regulate cellular metabolism.
Pic shows Mechanism of Hormonal action.