TY - JOUR T1 - Multiple Serotonin Receptors: Differential Binding of [<sup>3</sup>H]5-Hydroxytryptamine, [<sup>3</sup>H]Lysergic Acid Diethylamide and [<sup>3</sup>H]Spiroperidol JF - Molecular Pharmacology JO - Mol Pharmacol SP - 687 LP - 699 VL - 16 IS - 3 AU - STEPHEN J. PEROUTKA AU - SOLOMON H. SNYDER Y1 - 1979/11/01 UR - http://molpharm.aspetjournals.org/content/16/3/687.abstract N2 - [3H]5-Hydroxytryptamine (5-HT), [3H]lysergic acid diethylamide (LSD) and [3H]spiroperidol bind to membranes from the rat frontal cerebral cortex in a manner indicating a selective interaction with serotonin receptors. Differential drug potencies in competing for [3H]5-HT and [3H]spiroperidol binding sites suggest that these two [3H]ligands respectively label two distinct populations of receptors, while [3H]LSD labels both the [3H]5-HT and [3H]spiroperidol sites. After incubation of brain membranes with 30 nM spiroperidol, drug specificity of the residual [3H]LSD binding resembles that of receptors labeled by [3H]5-HT. Conversely, drug effects on [3H]LSD binding in the presence of 300 nM 5-HT resemble effects with [3H]spiroperidol. We propose that [3H]5-HT and [3H]-spiroperidol label distinct populations of serotonin receptors in rat brain, designated 5-HT1 and 5-HT2 receptors, respectively. [3H]LSD appears to bind to both receptors to a similar extent. ACKNOWLEDGMENTS We thank Richard M. Lebovitz for his skillful technical assistance and Pamela Morgan for manuscript preparation. ER -