Quipazine is a nonselective 5-HT receptors agonist. 5-HT receptors (Serotonin receptors) are a group of G protein-coupled receptors (GPCRs) and ligand-gated ion channels (LGICs) found in the central and peripheral nervous systems. They mediate both excitatory and inhibitory neurotransmission. Accumulating evidence indicates a role for at least 5 of the 14 5-HT receptor subtypes: 5-HT1A, 5-HT1B, 5-HT4, 5-HT6, and 5-HT7. The 5-HT receptors are activated by the neurotransmitter serotonin, which acts as their natural ligand. The 5-HT receptors modulate the release of many neurotransmitters, as well as many hormones. Therefore, the 5-HT receptors influence various biological and neurological processes such as aggression, anxiety, appetite, cognition, learning, memory, mood, nausea, sleep, andthermoregulation.

The 5-HT3 receptor is a member of the Cys-loop family of LGIC. Therefore, it differs from all other 5-HT receptors whose actions are mediated via G proteins. 5-HT3 receptors are located in both the peripheral (PNS) and central (CNS) nervous systems. Activation of these receptors in the PNS suggest they play a role in a variety of sympathetic, parasympathetic and sensory functions. Studies have suggested many diverse potential disease targets that might be amenable to alleviation by 5-HT3 receptor selective compounds but to date only two applications have been fully realised in the clinic: the treatment of emesis and irritable-bowel syndrome.

Quipazine is a broad-spectrum 5-HT receptor agonist.

Quipazine binds to a range of different 5-HT receptors, but particularly to the 5-HT2A and 5-HT3 subtypes. Therefore, Quipazine exhibits antidepressant and oxytocic activities. Besides, Quipazine also shows antiviral activity against SARS-CoV-2. Quipazine produces a head-twitch response and other psychedelic-consistent effects in animal studies including in mice, rats, and monkeys. Meanwhile, Quipazine shows antagonistic properties on the rat vagus nerve and inhibition of 5-HT release. Thus, Quipazine has the potential for the research of neurological diseases.

All in all, Quipazine is a piperazine-based nonselective 5-HT receptor agonist with antidepressant and oxytocic activities.

References:

[1]. Yohn CN, et, al. Mol Brain. 2017 Jun 24;10(1):28. 

[2]. Thompson AJ, et, al. Curr Pharm Des. 2006;12(28):3615-30.

[3]. Mok E, et, al. Appetite. 2000 Jun;34(3):313-25.