Receptor antagonism

Receptor antagonism occurs when a substance, called an antagonist, binds to a cell's receptor (a protein that detects signals like hormones or neurotransmitters) but does not activate it. Instead, it blocks or prevents other active signals from attaching and triggering a response. Think of it like a key that fits into a lock but doesn’t turn—it stops the normal key from opening the door. This is useful in medicine to prevent overactivation of certain pathways, such as reducing symptoms of diseases or blocking harmful signals.