title: Local inflammation increases vanilloid receptor 1 expression within distinct subgroups of DRG neurons.
abstract: Vanilloid receptor 1 (VR1) is essential to the development of inflammatory hyperalgesia. We investigated whether inflammation can increase in VR1 positive neuronal profiles in rat DRG neurons using histochemical methods. We also used size frequency analysis and double staining with several neuronal markers to investigate whether or not inflammation alters VR1 expression. Inflammation induced a 1.5-fold increase in percentage of VR1-like immunoreactivity (LI) positive profiles per total neuronal profiles, suggesting that the number of heat and pH sensitive neurons increase during inflammation. Area frequency histograms showed that VR1 expression increased in small and medium-sized neurons after inflammation. Double labeling of VR1 with NF200 showed that VR1 positive neurons with NF200 positive profiles significantly increased, indicating that the medium-sized VR1 positive neurons were neurons with myelinated A-fibers. Local inflammation thus increases in VR1 protein level within distinct subgroups of DRG neurons that may participate in the development and maintenance of inflammatory hyperalgesia.
authors.affiliation: Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kamikyo-ku, Kyoto, Japan.
authors.forename: Fumimasa
authors.initials: F
authors.lastname: Amaya
authors.forename: Kentaro
authors.initials: K
authors.lastname: Oh-hashi
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Naruse
authors.forename: Norio
authors.initials: N
authors.lastname: Iijima
authors.forename: Masashi
authors.initials: M
authors.lastname: Ueda
authors.forename: Goshun
authors.initials: G
authors.lastname: Shimosato
authors.forename: Makoto
authors.initials: M
authors.lastname: Tominaga
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Masaki
authors.initials: M
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D048429:Cell Size; D005727:Ganglia, Spinal / Q000378:metabolism* / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007249:Inflammation / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011955:Receptors, Drug / Q000096:biosynthesis*
chemical_list: D012333:RNA, Messenger; D011955:Receptors, Drug; D015740:Calcitonin Gene-Related Peptide