Preliminary Evidence of a Serotonin (5-HT-1-Like) Component to the Prolactin Response to Buspirone Challenge in Humans

To the Editor.—  The role of serotonin 1 (5-HT-1—like) receptors in the action of psychopharmacologic agents and in psychiatric disorders is an increasing focus of research.¹ However, there are few agents available for clinical use that assess the function of 5-HT-1—like receptors in humans.Buspirone hydrochloride (Buspar), a nonbenzodiazepine compound currently marketed as an anxiolytic, is reported to have high affinity for the central 5-HT-la receptor.² Hence, examination of neuroendocrine responses (eg, prolactin [PRL], growth hormone [GH], corticotropin [ACTH], cortisol [CORT]) to acute challenge with buspirone^3-6 may enable an assessment of 5-HT-la receptor sensitivity in humans.³ However, since buspirone is reported to have antidopamine activity in some,⁷ although not all,⁸ studies, the PRL response to buspirone challenge, in particular, may be confounded by its action on central dopaminergic neurons. In fact, some have suggested that the PRL response to buspirone challenge is due to