Partial Agonist
A ligand that binds to and activates a receptor but produces a submaximal response even at full receptor occupancy, possessing both agonist and antagonist properties depending on the level of endogenous agonist present. In the presence of a full agonist, a partial agonist can act as a functional antagonist by competing for receptor binding while producing a lower maximal effect.
Examples
- Buprenorphine: partial agonist at mu-opioid receptors, ceiling effect on respiratory depression
- Aripiprazole: partial agonist at dopamine D2 receptors, stabilizes dopaminergic tone
- Pindolol: partial agonist at beta-adrenergic receptors with intrinsic sympathomimetic activity
Did You Know?
A ligand that binds to and activates a receptor but produces a submaximal response even at full receptor occupancy, possessing both agonist and antagonist properties depending on the level of …