Sarpogrelate hydrochloride (MCI-9042) , a selective 5-HT2 antagonist, has been widely used as an anti-platelet agent for the treatment of PAD. Target: 5-HT2 Recepter Sarpogrelate is a drug which acts as an antagonist at the 5HT2A and 5-HT2B receptors. Sarpogrelate hydrochloride was shown to have the same affinity as ritanserin for 5-HT2A receptors, with a Ki value of 8.39 nM. Sarpogrelate hydrochloride lacked prominent 5-HT1-like, 5-HT3, beta, H1, H2 and M3 antagonist activity and weakly blocked alpha 1-adrenoceptors (pKB = 6.30). (S)-M-1 showed weak affinity for 5-HT1-like receptors (pKB = 6.30), alpha 1- (pKB = 6.80) and beta- (pKB = 6.54) adrenoceptors, while (R)-M-1 was a weak antagonist at histamine H1 receptors (pKB = 6.49). After 12 weeks of sarpogrelate administration, FBF and LBF responses during RH showed significant increases from 13.2 +/- 1.7 to 18.1 +/- 2.2 mL/min per 100 mL tissue (P < 0.01) and from 8.2 +/- 0.9 to 14.2 +/- 2.1 mL/min per 100 mL tissue (P < 0.05), respectively. Sarpogrelate hydrochloride -induced augmentation of FBF and LBF responses to RH was maintained at 24 weeks. Long-term oral administration of sarpogrelate improves vascular function in patients with PAD.

Sevoflurane (Fluoromethyl), a noncompetitive inhibitor of 5-HT3 receptor, acts as a low-soluble inhalation anesthetics.

Niaprazine is a histamine H1-receptor antagonist with marked sedative properties. Niaprazine has antihistamine and antiserotonin activities and can be used for sleep disorder research[1][2]. Niaprazine exhibits a low affinity for the vesicular monoamine transporter and for D2, α2, β, H1 and mAch receptors. Niaprazine, particularly the (+)stereoisomer, has a higher affinity for α1 (Ki = 77 nM) and 5-HT2 (Ki = 25 nM) binding sites, but is poorly recognized by 5-HT1A and 5-HT1B binding sites[2]. Niaprazine (60 mg/kg; i.p.; once) treatment increases rat brain 5-hydroxyindole acetic acid (5-HIAA) concentrations 30 min after treatment, and reduced them at 3-8 hr after treatment. Niaprazine also produces a short-lasting depletion of rat brain noradrenaline (NA) and dopamine (DA)[3]. Animal Model: Male Sprague-Dawley rats (150-200 g)[3] [1]. D Scherman, et al. Molecular pharmacology of niaprazine. Prog Neuropsychopharmacol Biol Psychiatry. 1988;12(6):989-1001. [2]. P G Rossi, et al. Niaprazine in the treatment of autistic disorder. J Child Neurol. 1999 Aug;14(8):547-50. [3]. P E Keane, et al. The effect of niaprazine on the turnover of 5-hydroxytryptamine in the rat brain. Neuropharmacology. 1982 Feb;21(2):163-9.

Litoxetine is a selective 5-HT uptake inhibitor and is a 5-HT3 receptor antagonist. Litoxetine acts as an antidepressant and has shown antiemetic properties in ferrets. Litoxetine (1 and 10 mg/kg i.v.) dose-dependently reduced the number of regurgitations and vomiting and delayed the onset of vomiting. Litoxetine has an affinity for brain 5HT3 receptors (Ki = 85 nM).

Aplindore Fumarate (DAB-452) is a small molecule dopamine D2 receptor partial agonist.Aplindore Fumarate exhibits high affinity for dopamine D2 and D3 receptors, and low affinity for dopamine D4, 5-hydroxytryptophan (5-HT2), and α1-adrenergic receptors.Aplindore Fumarate is used in the study of Parkinson's disease and schizophrenia. Fumarate can be used to study Parkinson's and schizophrenia.