5-HT1A receptor partial agonist (buspirone)
Binding of a partial agonist to the 5-HT1A receptor causes the dissociation of inhibitory G-proteins. The G-protein alpha sub-unit binds to and inhibits adenylate cyclase. This prevents the conversion of ATP to cAMP and the initiation of other secondary messenger signaling mechanisms, hence cell depolarisation is inhibited.
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References
Other peripheral mediators: 5-hydroxytryptamine and purines. In: Pharmacology, 4th edition. Rang HP, Dale MM and Ritter JM. Edinburgh, UK: Harcourt Publishers Ltd, 2001:539–49