title: Differential photoaffinity labelling of serotonin-S2 receptors and histamine-H1 receptors using 7-azidoketanserin.
abstract: 7-Azidoketanserin, a potent photoaffinity probe for serotonin-S2 receptors was shown to irreversibly photoinactivate histamine-H1 receptors as well. The photolabelling of H1-receptors could be prevented by several selective histamine-H1 antagonists. In guinea pig cerebellum, a brain area that is highly enriched in H1-receptors, photolabelling could be directed exclusively to these receptors by adding a high concentration of pipamperone, which selectively blocks serotonin-S2 receptors. In rat pre-frontal cortex, a region that is enriched in serotonin-S2 receptors, pyrilamine was used to block H1-receptors, thereby directing the photolabelling exclusively to S2-receptors.
mesh_terms: D000345:Affinity Labels / Q000378:metabolism; D000818:Animals; D001386:Azides / Q000378:metabolism*; D001667:Binding, Competitive; D002090:Butyrophenones / Q000494:pharmacology; D002531:Cerebellum / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D005260:Female; D006168:Guinea Pigs; D007650:Ketanserin / Q000031:analogs & derivatives*; D010782:Photolysis; D010880:Piperidines / Q000378:metabolism*; D011738:Pyrilamine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011968:Receptors, Histamine / Q000378:metabolism*; D011969:Receptors, Histamine H1 / Q000378:metabolism*; D011985:Receptors, Serotonin / Q000378:metabolism*; D013134:Spiperone / Q000378:metabolism
chemical_list: D000345:Affinity Labels; D001386:Azides; D002090:Butyrophenones; D010880:Piperidines; D011968:Receptors, Histamine; D011969:Receptors, Histamine H1; D011985:Receptors, Serotonin; D013134:Spiperone; C005569:pipamperone; C044880:7-azidoketanserin; D007650:Ketanserin; D011738:Pyrilamine