Posted by zeugma on March 29, 2006, at 19:29:59
In reply to Re: 5ht2 antagonists » dondon, posted by linkadge on March 29, 2006, at 18:28:39
There is actually evidence that buspirone aids in the downregulation of the 5-HT2A/C receptors:
: Pharmacopsychiatry. 2006 Jan;39(1):1-8.
Combined treatment with citalopram and buspirone: effects on serotonin 5-HT2A and 5-HT2C receptors in the rat brain.Syvalahti E, Penttila J, Majasuo H, Palvimaki EP, Laakso A, Hietala J.
Department of Pharmacology and Clinical Pharmacology, University of Turku, 20520 Turku, Finland. erkka.syvalahti@utu.fi
INTRODUCTION: We wanted to elucidate whether the proposed advantages of citalopram-buspirone combination treatment are related to changes in 5-HT(2A/C) receptor-mediated neurotransmission. METHODS: The affinity of buspirone to 5-HT2A and 5-HT2C receptors was measured in vitro, and the influence of buspirone on 5-HT2C receptor-mediated phosphoinositide hydrolysis was estimated. Four groups of rats received citalopram (10 mg/kg), buspirone (6 mg/kg), citalopram-buspirone combination, or saline once a day s.c. for 14 days. Treatment effects on 5-HT2A and 5-HT2C receptors were investigated by receptor autoradiography with antagonist and agonist radioligands. RESULTS: Buspirone was found to be a weak 5-HT2C receptor antagonist, with a low affinity for 5-HT2A and 5-HT2C receptors. Repeated buspirone-citalopram combination treatment markedly decreased [3H]ketanserin and [125I]DOI binding to 5-HT2A receptors. Repeated administration of buspirone and buspirone-citalopram combination increased the affinity of [3H]mesulergine toward 5-HT2C receptors, and buspirone-citalopram combination also decreased [125I]DOI binding to 5-HT2C receptors. DISCUSSION: We suggest that downregulation of brain 5-HT2A receptors and possibly of 5-HT2C receptor agonist sites is involved in the beneficial clinical effects of buspirone-SSRI augmentation treatment. Furthermore, a conversion of brain 5-HT2C receptors from high- to low-affinity state may provide an additional mechanism for the anti-anxiety effects of buspirone.>>
Amitriptyline and nortriptyline are both powerful antagonists of these receptors. Possibly this is why i found addition of buspirone to nortriptyline beneficial.
-z
poster:zeugma
thread:626219
URL: http://www.dr-bob.org/babble/20060329/msgs/626301.html