Agonist

New findings that broaden the conventional definition of pharmacology demonstrate that ligands can concurrently behave as agonist and antagonists at the same receptor, depending on effector pathways or tissue type.

[11] These co-agonists are both required to induce the conformational change needed for the NMDA receptor to allow flow through the ion channel, in this case calcium.

[11] An aspect demonstrated by the NMDA receptor is that the mechanism or response of agonists can be blocked by a variety of chemical and biological factors.

[11] These differences show that agonists have unique mechanisms of action depending on the receptor activated and the response needed.

[9][10] The goal and process remains generally consistent however, with the primary mechanism of action requiring the binding of the agonist and the subsequent changes in conformation to cause the desired response at the receptor.

The smaller the EC50 value, the greater the potency of the agonist, the lower the concentration of drug that is required to elicit the maximum biological response.