Discrimination of Multiple [3H]5‐Hydroxytryptamine Binding Sites by the Neuroleptic Spiperone in Rat Brain

Certain neuroleptic drugs, such as spiperone and (+) butaclamol, can discriminate between two populations of [3H]5‐hydroxytryptamine ([3H]5‐HT) binding sites in rat brain. The butyrophenone neuroleptic spiperone shows the greatest selectivity for these two binding sites, having at least a 3000‐fold difference between its dissociation constants (2‐12 nM versus 35,000 nM) for the high‐ and low‐affinity sites, respectively. Inhibition of [3H]5‐HT binding by spiperone in rat frontal cortex and corpus striatum yields distinctly biphasic inhibition curves with Hill slopes significantly less than unity. Results from nonlinear regression analysis of these inhibition studies were consistent with a two‐site model in each brain region. In the frontal cortex the high‐affinity neuroleptic sites comprised about 60% of the total [3/H]5‐HT binding sites whereas in the corpus striatum they accounted for only 20% of the sites. Furthermore, saturation studies of [3H]5‐HT binding assayed in the absence or presence of 1 μM‐spiperone (a concentration that completely blocks the high‐affinity site while having minimal activity at the low‐affinity site) reveal a parallel shift in the Scatchard plot with no change in the dissociation constant of [3H]5‐HT, but a significant decrease (64% in frontal cortex or 28% in corpus striatum) in the number of specific binding sites. These observations are consistent with the existence of at least two populations of [3H]5‐HT binding sites having a differential regional distribution in rat brain.

[1]  S. Snyder,et al.  3H-Spiroperidol labels serotonin receptors in rat cerebral cortex and hippocampus. , 1978, European journal of pharmacology.

[2]  R. A. Lovell,et al.  Stereospecific receptor sites for d-lysergic acid diethylamide in rat brain: effects of neurotransmitters, amine antagonists, and other psychotropic drugs. , 1976, Molecular pharmacology.

[3]  R. Mccall,et al.  Serotonergic facilitation of facial motoneuron excitation , 1979, Brain Research.

[4]  J. Black,et al.  Definition and Antagonism of Histamine H2-receptors , 1972, Nature.

[5]  J. Fields,et al.  3H-Spiroperidol binding to two receptor sites in both the corpus striatum and frontal cortex of rat brain. , 1978, European journal of pharmacology.

[6]  P. Molinoff,et al.  Simultaneous determination of beta-1 and beta-2-adrenergic receptors in tissues containing both receptor subtypes. , 1979, Molecular pharmacology.

[7]  S. Snyder,et al.  Serotonin and lysergic acid diethylamide binding in rat brain membranes: relationship to postsynaptic serotonin receptors. , 1976, Molecular pharmacology.

[8]  H. Gerschenfeld,et al.  Ionic mechanisms and receptor properties underlying the responses of molluscan neurones to 5‐hydroxytryptamine , 1974, The Journal of physiology.

[9]  O. H. Lowry,et al.  Protein measurement with the Folin phenol reagent. , 1951, The Journal of biological chemistry.

[10]  S H Snyder,et al.  Multiple serotonin receptors: differential binding of [3H]5-hydroxytryptamine, [3H]lysergic acid diethylamide and [3H]spiroperidol. , 1979, Molecular pharmacology.

[11]  A. Herbet,et al.  Multiple receptors for serotonin in the rat brain. , 1980, Advances in biochemical psychopharmacology.

[12]  John Hughes,et al.  Endogenous opioid peptides: multiple agonists and receptors , 1977, Nature.

[13]  B. Levy,et al.  Selective interactions with beta adrenergic receptors. , 1970, Federation proceedings.

[14]  P. Cuatrecasas,et al.  Multiple opiate receptors: different regional distribution in the brain and differential binding of opiates and opioid peptides. , 1979, Molecular pharmacology.

[15]  W. Pettinger,et al.  A functional basis for classification of α-adrenergic receptors , 1977 .

[16]  J. Deniau,et al.  Decrease of [3H]5‐HT high affinity binding and 5‐HT adenylate cyclase activation after kainic acid lesion in rat brain striatum , 1979, Journal of neurochemistry.

[17]  R. Lefkowitz,et al.  Quantitative resolution of beta-adrenergic receptor subtypes by selective ligand binding: application of a computerized model fitting technique. , 1979, Molecular pharmacology.

[18]  J. Thompson,et al.  The effects of morphine- and nalorphine- like drugs in the nondependent and morphine-dependent chronic spinal dog. , 1976, The Journal of pharmacology and experimental therapeutics.

[19]  J. Deniau,et al.  High-affinity binding of (3H) 5-hydroxytryptamine to brain synaptosomal membranes: comparison with (3H) lysergic acid diethylamide binding. , 1978, Molecular pharmacology.

[20]  N. Birdsall,et al.  The binding of agonists to brain muscarinic receptors. , 1978, Molecular pharmacology.

[21]  M. Nirenberg,et al.  Adenylate cyclase and acetylcholine release regulated by separate serotonin receptors of somatic cell hybrids. , 1979, Proceedings of the National Academy of Sciences of the United States of America.

[22]  J. Leysen,et al.  A serotonergic component of neuroleptic receptors. , 1977, Archives internationales de pharmacodynamie et de therapie.

[23]  H. Yamamura,et al.  The influence of guanyl-5'-yl imidodiphosphate and sodium on muscarinic receptor binding in the rat brain and longitudinal muscle of the rat ileum. , 1980, Life sciences.

[24]  S. Snyder,et al.  Multiple α2‐Noradrenergic Receptor Sites in Rat Brain: Selective Regulation of High‐Affinity [3H] Clonidine Binding by Guanine Nucleotides and Divalent Cations , 1980 .

[25]  S. Snyder,et al.  Binding interactions of lysergic acid diethylamide and related agents with dopamine receptors in the brain. , 1976, Molecular pharmacology.

[26]  A. Herbet,et al.  Characteristics of central 5-HT receptors and their adaptive changes following intracerebral 5,7-dihydroxytryptamine administration in the rat. , 1978, Molecular pharmacology.

[27]  S. Snyder,et al.  Distinct α-noradrenergic receptors differentiated by binding and physiological relationships , 1979 .

[28]  S. Snyder,et al.  Characteristics of histamine H1-receptors in peripheral tissues labeled with [3H]mepyramine. , 1979, The Journal of pharmacology and experimental therapeutics.

[29]  K. Beaumont,et al.  Muscimol binding in rat brain: Association with synaptic GABA receptors , 1978, Brain Research.

[30]  J. Kebabian,et al.  Multiple receptors for dopamine , 1979, Nature.

[31]  Y. Nomura,et al.  Modifications of central 5-hydroxytryptamine binding sites in synaptic membranes from rat brain after long-term administration of tricyclic antidepressants. , 1979, European journal of pharmacology.