Lower affinity for D2 results in faster unbinding. This phenomenon is described as which process?

Lower affinity for D2 results in faster unbinding. This phenomenon is described as which process?

• A. Receptor dissociation
• B. D2 receptor upregulation
• C. Dopamine synthesis inhibition
• D. Receptor internalization

Answer: (A)

Understanding receptor-ligand binding kinetics helps explain this. Affinity describes how tightly a ligand stays bound and is linked to how fast it unbinds—the off-rate. When affinity is lower, the off-rate is higher, so the ligand dissociates from the receptor more quickly. This unbinding is the receptor dissociation process. The other options describe different phenomena: upregulation is increasing receptor numbers, dopamine synthesis inhibition affects production of the ligand, and receptor internalization is removal of the receptor from the cell surface.

Understanding receptor-ligand binding kinetics helps explain this. Affinity describes how tightly a ligand stays bound and is linked to how fast it unbinds—the off-rate. When affinity is lower, the off-rate is higher, so the ligand dissociates from the receptor more quickly. This unbinding is the receptor dissociation process. The other options describe different phenomena: upregulation is increasing receptor numbers, dopamine synthesis inhibition affects production of the ligand, and receptor internalization is removal of the receptor from the cell surface.