title: Timberol® Inhibits TAAR5-Mediated Responses to Trimethylamine and Influences the Olfactory Threshold in Humans.
abstract: In mice, trace amine-associated receptors (TAARs) are interspersed in the olfactory epithelium and constitute a chemosensory subsystem that is highly specific for detecting volatile amines. Humans possess six putative functional TAAR genes. Human TAAR5 (hTAAR5) is highly expressed in the olfactory mucosa and was shown to be specifically activated by trimethylamine. In this study, we were challenged to uncover an effective blocker substance for trimethylamine-induced hTAAR5 activation. To monitor blocking effects, we recombinantly expressed hTAAR5 and employed a commonly used Cre-luciferase reporter gene assay. Among all tested potential blocker substances, Timberol®, an amber-woody fragrance, is able to inhibit the trimethylamine-induced hTAAR5 activation up to 96%. Moreover, human psychophysical data showed that the presence of Timberol® increases the olfactory detection threshold for the characteristic fishy odor of trimethylamine by almost one order of magnitude. In conclusion, our results show that among tested receptors Timberol® is a specific and potent antagonist for the hTAAR5-mediated response to trimethylamine in a heterologous system. Furthermore, our data concerning the observed shift of the olfactory detection threshold in vivo implicate that hTAAR5 or other receptors that may be inhibited by Timberol® could be involved in the high affinity olfactory perception of trimethylamine in humans.
authors.affiliation: Department of Cell Physiology, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Ivonne
authors.initials: I
authors.lastname: Wallrabenstein
authors.affiliation: Symrise AG, Holzminden, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Singer
authors.affiliation: Symrise AG, Holzminden, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Panten
authors.affiliation: Department of Cell Physiology, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Hanns
authors.initials: H
authors.lastname: Hatt
authors.affiliation: Department of Cell Physiology, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Günter
authors.initials: G
authors.lastname: Gisselmann
mesh_terms: D000328:Adult; D002460:Cell Line; D004056:Differential Threshold / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008744:Methylamines / Q000494:pharmacology*; D008875:Middle Aged; D009822:Oils, Volatile / Q000494:pharmacology*; D009831:Olfactory Mucosa / Q000187:drug effects* / Q000378:metabolism; D055696:Olfactory Perception / Q000187:drug effects; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014934:Wood / Q000737:chemistry; D000095383:Trace Amine-Associated Receptors
chemical_list: D008744:Methylamines; D009822:Oils, Volatile; D043562:Receptors, G-Protein-Coupled; D011994:Recombinant Proteins; C583307:TAAR5 protein, human; D000095383:Trace Amine-Associated Receptors; C023336:trimethylamine