Rabbit Anti-Human TAAR1 (internal) Polyclonal antibody

Individuals of many species rely on odors to communicate, find breeding partners, locate resources and sense dangers. In vertebrates, odorants are detected by chernosensory receptors of the olfactory system. One class of these receptors, the trace amineassociated receptors (TAARs), was recently suggested to mediate male sexual interest and mate choice. Here we tested this hypothesis in mice by generating a cluster deletion mouse (Taar2-9(-/-)) lacking all TAARs expressed in the olfactory epithelium, and evaluating transduction pathways from odorants to TAARs, neural activity and behaviors reflecting sexual interest. We found that a urinary volatile amine, isobutylamine (IBA), was a potent ligand for TAAR3 (but not TAAR1, 4, 5, and 6). When males were exposed to IBA, brain regions associated with sexual behaviors were less active in Taar2-9(-/-) than in wild type males. Accordingly, Taar2-9(-/-) males spent less time sniffing both the urine of females and pure IBA than wild type males. This is the first demonstration of a comprehensive transduction pathway linking odorants to TAARs and male sexual interest. Interestingly, the concentration of IBA in female urine varied across the estrus cycle with a peak during estrus. This variation in IBA concentration may represent a simple olfactory cue for males to recognize receptive females. Our results are consistent with the hypothesis that IBA and TAARs play an important role in the recognition of breeding partners and mate choice.

Background: 2,4,5-Trimethoxyamphetamine (TMA-2) is a potent psychedelic compound. Structurally related 4-alkyloxy-substituted 2,5-dimethoxyamphetamines and phenethylamine congeners (2C-O derivatives) have been described but their pharmacology is mostly undefined. Therefore, we examined receptor binding and activation profiles of these derivatives at monoamine receptors and transporters. Methods: Receptor binding affinities were determined at the serotonergic 5-HT1A, 5-HT2A, and 5-HT2C receptors, trace amine-associated receptor 1 (TAAR1), adrenergic alpha(1) and alpha(2) receptors, dopaminergic D-2 receptor, and at monoamine transporters, using target-transfected cells. Additionally, activation of 5-HT2A and 5-HT2B receptors and TAAR1 was determined. Furthermore, we assessed monoamine transporter inhibition. Results: Both the phenethylamine and amphetamine derivatives (K-i = 8-1700 nM and 61-4400 nM, respectively) bound with moderate to high affinities to the 5-HT2A receptor with preference over the 5-HT1A and 5-HT2C receptors (5-HT2A/5-HT1A = 1.4-333 and 5-HT2A/5-HT2C = 2.1-14, respectively). Extending the 4-alkoxy-group generally increased binding affinities at 5-HT2A and 5-HT2C receptors but showed mixed effects in terms of activation potency and efficacy at these receptors. Introduction of a terminal fluorine atom into the 4-ethoxy substituent by trend decreased, and with progressive fluorination increased affinities at the 5-HT2A and 5-HT2C receptors. Little or no effect was observed at the 5-HT1A receptor for any of the substances tested (K-i >= 2700 nM). Phenethylamines bound more strongly to the TAAR1 (K-i = 21-3300 nM) compared with their amphetamine analogs (K-i = 630-3100 nM). Conclusion: As seen with earlier series investigated, the 4-alkyloxy-substituted 2,5-dimethoxyamphetamines and phenethylamines share some trends with the many other phenethylamine pharmacophore containing compounds, such as when increasing the size of the 4-substituent and increasing the lipophilicity, the affinities at the 5-HT2A/C subtype also increase, and only weak 5-HT2A/C subtype selectivities were achieved. At least from the binding data available (i.e., high affinity binding at the 5-HT2A receptor) one may predict mainly psychedelic-like effects in humans, at least for some of the compound investigated herein.