Downregulation is how a cell responds to being signalled at constantly: it reduces the number of receptors it puts on display, or makes the ones it has less responsive. The switch is still being pressed, but the cell has quietly removed some of the switches. It is a normal adjustment rather than damage, and it generally reverses when the signal eases, though how quickly varies a great deal between receptors and is often not well established.

Why it matters here

It is the reason a steady signal and an intermittent one are not biologically equivalent, and part of why the body releases many of its own hormones in bursts rather than continuously. It also explains why continued exposure to an agonist does not simply keep producing the same response.

Also called

• downregulation
• down-regulation
• down regulation
• receptor downregulation
• desensitisation
• desensitization
• tolerance
• upregulation

Desensitisation and tolerance are used for closely related ideas. Upregulation is the same process in reverse, with a cell adding receptors when a signal becomes scarce.

Compounds carrying this term

None on file yet. This term is in the controlled vocabulary but no compound record currently uses it — which is a statement about our coverage, not about the term.

See also

• Receptor — Body and drug basics
• Agonist — Body and drug basics
• Peak and trough — Body and drug basics
• Clearance — Body and drug basics