title: Adult rat odontoblasts lack noxious thermal sensitivity.
abstract: Dentin hypersensitivity is a common symptom treated in the dental clinic, yet the underlying cellular and molecular mechanisms are not clear. We hypothesized that odontoblasts detect noxious thermal stimuli by expressing temperature-sensing molecules, and investigated whether temperature-activated TRP channels (thermo-TRP channels), which are known to initiate temperature signaling, mediate temperature sensing in odontoblasts. mRNA expression of dentin sialophosphoprotein and collagenase type 1, odontoblast-specific proteins, was shown in acutely isolated adult rat odontoblasts by single-cell RT-PCR, while TRPV1, TRPV2, TRPM8, and TRPA1 were not detected. Application of noxious temperatures of 42 degrees C and 12 degrees C, as well as capsaicin, menthol, and icilin, agonists of thermo-TRP channels, failed to increase intracellular calcium concentration. Immunohistochemical study also revealed no expression of TRPV1. Thus, it is unlikely that odontoblasts serve as thermal sensors in teeth via thermo-TRP channels.
authors.affiliation: National Research Laboratory for Pain, Dental Research Institute and Department of Physiology, School of Dentistry, Seoul National University, 28-2 Yeongeon-Dong Chongno-Ku, Seoul 110-749, Korea.
authors.forename: K Y
authors.initials: KY
authors.lastname: Yeon
authors.forename: G
authors.initials: G
authors.lastname: Chung
authors.forename: M S
authors.initials: MS
authors.lastname: Shin
authors.forename: S J
authors.initials: SJ
authors.lastname: Jung
authors.forename: J S
authors.initials: JS
authors.lastname: Kim
authors.forename: S B
authors.initials: SB
authors.lastname: Oh
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003782:Dental Pulp / Q000166:cytology; D003807:Dentin Sensitivity / Q000378:metabolism*; D007180:Incisor; D009619:Nociceptors / Q000378:metabolism; D009804:Odontoblasts / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000502:physiology*; D050052:TRPC Cation Channels / Q000235:genetics / Q000378:metabolism*; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism; D013697:Thermosensing / Q000502:physiology*; D012668:Trigeminal Ganglion / Q000166:cytology / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D050052:TRPC Cation Channels; D050916:TRPV Cation Channels; C494484:TRPV1 receptor