Question

How could the same hormone have different, even opposite, effects on different cells (for example epinephrine in the peripheral circulatory system vs. at the heart)?

Answer 1

The same hormone can have different or opposite effects on different cells because,

• There can be many receptors for the same hormone. When bound to one receptor, the hormone may not follow the same pathway, as when bound to another.
• The same receptor may follow different signal transduction pathways in different cell types.
• Effector proteins inside the cell may interact in a different manner with the intracellular cascade promoted by the hormone.
• A hormone can also interact with receptors of other molecules.