title: Evidence for low brain penetration by the H1-receptor antagonist temelastine (SK&F 93944).
abstract: Competition by the potent selective H1-receptor antagonist temelastine (SK & F 93944) with [3H]mepyramine binding to mouse cortex H1-receptors has been measured in vitro and vivo. The data were compared with that obtained using the classical H1-receptor antagonists mepyramine and promethazine and indicated that temelastine has relatively low ability to penetrate the blood-brain barrier compared with the latter two compounds. These studies also revealed that temelastine has relatively low affinity for mouse cortex H1-receptors compared with its affinity for H1-receptors in guinea-pig ileum and cortex, suggesting that it may be a useful compound with which to investigate potential H1-receptor tissue and species-related differences.
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006634:Histamine H1 Antagonists / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D011398:Promethazine / Q000494:pharmacology; D011738:Pyrilamine / Q000378:metabolism; D011744:Pyrimidinones / Q000378:metabolism* / Q000494:pharmacology; D011969:Receptors, Histamine H1 / Q000378:metabolism; D014316:Tritium
chemical_list: D006634:Histamine H1 Antagonists; D011744:Pyrimidinones; D011969:Receptors, Histamine H1; D014316:Tritium; C049054:temelastine; D011398:Promethazine; D011738:Pyrilamine