Down-regulation

Definition

Down-regulation is the process by which a cell decreases the number of receptors for a particular hormone, reducing its sensitivity to that hormone. This mechanism helps maintain homeostasis when hormone levels are chronically elevated.

5 Must Know Facts For Your Next Test

1. Down-regulation occurs in response to high concentrations of a hormone over a prolonged period.
2. It involves internalization or degradation of hormone receptors on the cell surface.
3. This process prevents overstimulation and potential damage from excessive hormonal signaling.
4. Down-regulation can affect various hormones, including insulin and adrenaline.
5. It plays a critical role in conditions like type 2 diabetes, where cells become less responsive to insulin.

Review Questions

Related terms

Up-regulation: The increase in the number of receptors on the cell surface, enhancing sensitivity to a particular hormone.

Receptor Desensitization: A temporary inability of a receptor to respond to its ligand due to continuous exposure.

Hormone Resistance: A condition where cells fail to respond adequately to normal levels of hormones, often due to down-regulation.