Binding studies with the 5-HT1B receptor agonist [3H]CP-96,501 in brain tissues |
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Authors: | Lorraine A. Lebel B. Kenneth Koe |
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Abstract: | Binding studies in rat brain membranes have shown that [3H]CP-96,501 is a selective, high affinity radioligand for 5-HT1B receptors. Additional studies with [3H]CP-96,501 in brain tissues of several other species were undertaken to investigate its utility in detecting this receptor subtype. The presence of 5-HT1B receptors in brain membranes of the hamster and gerbil was demonstrated with [3H]CP-96,501. This finding was confirmed by [3H]5-HT binding experiments that also indicated the presence of other 5-HT1 subtypes (possibly 5-HT1D, 5-HT1E) in these species as well as the rat. Negligible specific binding of [3H]CP-96,501 was found in membranes of guinea pig brain, dog hypothalamus, bovine caudate, pig choroid plexus, and several human brain tissues, consistent with the reported absence of the 5-HT1B receptor subtype in these species. Autoradiographic examination of rat brain sections labeled by [3H]CP-96,501 showed a dense localization in areas known to be enriched in 5-HT1B receptors (e.g., globus pallidus, substantia nigra, superior colliculus, subiculum). On the other hand, brain sections of dog and guinea pig appeared to show no specific binding of [3H]CP-96,501 by autoradiography, in agreement with the lack of brain 5-HT1B receptors in these tissues. © 1992 Wiley-Liss, Inc. |
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Keywords: | [3H]3-(1,2,5,6-tetrahydro-4-pyridyl)-5-propoxyindole serotonin1B receptor rat hamster gerbil dog guinea pig |
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