Immunolabeling of Central Serotonin 5-HT1Dβ Receptors in the Rat, Mouse, and Guinea Pig with a Specific Anti-Peptide Antiserum |
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Authors: | X Langlois C Gérard M Darmon J Chauveau M Hamon S El Mestikawy |
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Institution: | INSERM U. 288, Neurobiologie Cellulaire et Fonctionnelle, Facultéde Médecine Pitié-Salpêtrière, Paris;and; Immunotech, Marseille, France |
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Abstract: | Abstract: A synthetic peptide (25 amino acids) corresponding to a specific portion of the third intracytoplasmic loop of the rat serotonin 5-HT1B/1Dβ receptor was coupled to keyhole limpet hemocyanin and injected monthly into rabbits. Anti-peptide antibodies were detected by enzyme-linked immunosorbent assay and characterized by immunoprecipitation of the 5-HT1B/1Dβ receptor in CHAPS-solubilized extracts from rat striatal membranes. Up to 60% of solubilized striatal serotonin- O -carboxymethylglycyl125I]iodotyrosinamide (125I]GTI; a selective 5-HT1B/1D radioligand) binding sites were immunoprecipitated and subsequently pharmacologically identified as 5-HT1B receptors. The remaining 40% of 125I]GTI binding sites were shown to be 5-HT1D receptors. In addition, these antibodies were successfully used in immunofluorescence experiments to detect the 5-HT1B/1Dβ, but not the 5-HT1D/1Dα, receptor in transiently transfected LLC-PK1 cells. Immunoautoradiographic experiments performed with brain sections from the rat, mouse, and guinea pig showed that the substantia nigra and globus pallidus contained the highest densities of 5-HT1Dβ receptor-like immunoreactivity. Comparison of the regional distribution of immunolabeling with that of the specific binding of 125I]GTI in the brain of these species further confirmed that the anti-peptide antibodies selectively recognized only the 5-HT1Dβ component of 125I]GTI specific receptor binding sites. |
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Keywords: | Serotonin 5-HT1Dβ receptor Immunolabeling study Serotonin-O-carboxymethylglycyl[125I]iodotyrosinamide Anti-peptide antibodies |
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