Several hormones utilize cyclic adenosine monophosphate (cAMP) as a second messenger. These hormones play vital roles in numerous physiological processes.
Hormones Using cAMP
cAMP acts as an intracellular signal that mediates the effects of various hormones. Here's a breakdown:
| Hormone | Function | Role of cAMP |
|---|---|---|
| Calcitonin | Regulates blood calcium levels and promotes bone construction. | cAMP mediates the effects of calcitonin on bone cells and calcium handling. |
| Glucagon | Elevates blood glucose levels. | cAMP triggers processes that break down glycogen and increase blood sugar. |
| Thyroid-Stimulating Hormone (TSH) | Stimulates the thyroid gland to release T3 and T4. | cAMP acts as the signal for TSH to release thyroid hormones. |
How cAMP Works
- Hormone Binding: A hormone binds to a receptor on the cell surface.
- Activation: This binding activates an enzyme called adenylyl cyclase.
- cAMP Production: Adenylyl cyclase converts ATP into cAMP.
- Intracellular Signaling: cAMP activates protein kinases, which then initiate a cascade of cellular responses.
Example
For instance, when glucagon binds to its receptor on liver cells, it elevates the concentration of intracellular cAMP. This increase in cAMP causes the activation of protein kinases that trigger glycogen breakdown, leading to increased blood glucose levels.
Additional Information
While calcitonin, glucagon, and thyroid-stimulating hormone are examples of hormones that use cAMP, it’s important to note that many other hormones also use cAMP as their secondary messenger. These are just a few of the key examples.
