title: Chronic restraint stress in rats suppresses sweet and umami taste responses and lingual expression of T1R3 mRNA.
abstract: Effects of chronic restraint stress on the taste responses to five basic taste qualities were investigated electrophysiologically in the rat chorda tympani. In addition, the mRNA expression for T1R3, the common G-protein-coupled receptor (GPCR) for sweet and umami tastes, was studied quantitatively by RT-PCR after such stress. Rats were restrained in a small cylindrical restrainer made of steel wire for 8h daily for 14 successive days. The integrated responses to sweet and umami tastes, as recorded from the chorda tympani, were significantly suppressed after such stress, but the other three basic taste responses were unaffected. Expression of T1R3 mRNA in the fungiform papillae, as estimated by RT-PCR, was slightly reduced by the stress, and a quantitative real time RT-PCR study revealed a significant suppression of T1R3 mRNA expression in the stress group. These results suggest that the observed stress-induced changes in taste sensation could be caused by a peripheral disorder of the transduction mechanism in taste-receptor cells, involving in particular a stress-induced inhibition of T1R3 expression.
authors.affiliation: Division of Integrative Physiology, Department of Functional, Morphological and Regulatory Science, Tottori University Faculty of Medicine, Yonago, Tottori 683, Japan.
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Okamoto
authors.forename: Michio
authors.initials: M
authors.lastname: Miyoshi
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Imoto
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ryoke
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D008036:Lingual Nerve / Q000378:metabolism* / Q000503:physiopathology*; D008297:Male; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D051381:Rats; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D012149:Restraint, Physical / Q000009:adverse effects / Q000502:physiology; D011984:Sensory Receptor Cells / Q000502:physiology*; D013649:Taste / Q000235:genetics; D013650:Taste Buds / Q000378:metabolism* / Q000503:physiopathology; D055697:Taste Perception / Q000502:physiology*; D013997:Time Factors
chemical_list: D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; C431926:taste receptors, type 1