5-Hydroxytryptamine receptor 2B (for 5-HT2B), 5-Hydroxytryptamine receptor 2C (for 5-HT2C) (5-HT2B, 5-HT2C)

5-Hydroxytryptamine receptor 2B (5-HT2B) and 5-Hydroxytryptamine receptor 2C (5-HT2C) are subtypes of serotonin receptors, encoded by the HTR2B and HTR2C genes respectively. Both belong to the G protein-coupled receptor (GPCR) superfamily and canonically signal via Gq/G11 proteins, resulting in activation of phospholipase C and increased levels of IP3/DAG. 5-HT2C is mainly expressed in the central nervous system, where it modulates neurotransmitter release—particularly dopamine—and is implicated in mood, appetite, and behavior regulation. 5-HT2B is primarily found in peripheral tissues such as the heart, where it regulates cardiac fibroblast proliferation and heart valve function, in addition to roles in the nervous system and gastrointestinal tract. Overactivation of 5-HT2B has been directly linked to drug-induced cardiac valvulopathy, making its antagonism a therapeutic interest in certain conditions. A variety of agonists and antagonists targeting these receptors are in clinical use or development, with therapeutic indications principally in neuropsychiatric disease (5-HT2C antagonism/agonism) and in the management or avoidance of cardiac side effects (5-HT2B antagonism).

Other names

Serotonin receptor 2B (for 5-HT2B)Serotonin receptor 2C (for 5-HT2C)HTR2B (gene for 5-HT2B)HTR2C (gene for 5-HT2C)5-HT2 receptor subtype B/C5-HT2BR5-HT2CR

Agonists: Activate serotonin signaling via Gq/G11 pathway, increasing intracellular IP3 and DAG, resulting in excitatory neurotransmission and cellular responses. Antagonists: Block serotonin binding, inhibiting downstream signaling, often used to counteract overactivation (e.g., prevent drug-induced cardiac valvulopathy with 5-HT2B antagonists). Some drugs exhibit biased agonism or signaling pathway selectivity (e.g. pathway-selective activation/inhibition).