5-HT is involved in a variety of physiological and biological processes. In the brain, 5-HT has been found to affect sleep, mood, appetite, anxiety, aggression, perception, pain, and cognition¹. Signaling of 5-HT is mediated by receptors that are located on the cell membrane of neurons and most other cells in the body. The 5-HT2 family consists of three G-protein coupled receptors (GPCRs): 5-HT2A, 5-HT2B, and 5-HT2C². Like other members, they are transmembrane proteins consisting of seven membrane-spanning α-helical segments with an extracellular N-terminus and an intracellular C-terminus. The binding of 5-HT to one of its receptors is thought to elicit a conformational change that activates associated heterotrimeric G proteins and recruits other downstream signaling/scaffolding molecules, such as GPCR kinases and β-arrestins.

5-HT2B receptors have been found to be present in both rodent and human tissues, particularly in the cardiovascular system, gastrointestinal tract, bone, and central nervous system². Only low expression levels are found in the brain and blood. The highest expression levels are found in the stomach fundus³.

Over-expression of 5-HT2B receptors in hearts of transgenic mice results in cardiac hypertrophy and decreased ventricular function due to enhanced extracellular matrix (ECM) and remodeling. Likewise, genetic deletion of 5-HT2B receptors was shown to lead to ventricular dilation and incomplete cardiac development⁵.