title: Noradrenaline release in the median preoptic nucleus area caused by hemorrhage in the rat.
abstract: The present study was designed to examine whether noradrenergic projections from the A1 cell group in the ventrolateral medulla to the median preoptic nucleus (MnPO) transmit information from the peripheral baroreceptors. In urethane-anesthetized male rats, extracellular concentrations of noradrenaline (NA) in the region of the MnPO in response to hemorrhage (5 or 10 ml/kg) were monitored with in vivo microdialysis methods. Hemorrhage significantly increased the NA release in the MnPO area. The enhancement of NA release in the MnPO area caused by hemorrhage was significantly attenuated by previous injections of the local anesthetic lidocaine (2 %, 0.2 microl), but not by saline (0.2 microl), into the A1 region. These results suggest that the noradrenergic projections from the A1 region are important for carrying the peripheral baroreceptor information to the MnPO.
authors.affiliation: Department of Curriculum, Teaching and Memory, Naruto University of Education, Takashima, Naruto-cho, Naruto, Tokushima 772-8502, Japan. tanakaj@naruto-u.ac.jp
authors.forename: Junichi
authors.initials: J
authors.lastname: Tanaka
authors.forename: Satoko
authors.initials: S
authors.lastname: Hatakenaka
authors.forename: Hiroko
authors.initials: H
authors.lastname: Miyakubo
authors.forename: Masahiko
authors.initials: M
authors.lastname: Nomura
mesh_terms: D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D001769:Blood / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005110:Extracellular Space / Q000378:metabolism; D006470:Hemorrhage / Q000378:metabolism* / Q000503:physiopathology; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D017551:Microdialysis / Q000379:methods; D009638:Norepinephrine / Q000378:metabolism*; D011301:Preoptic Area / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D000779:Anesthetics, Local; D012965:Sodium Chloride; D008012:Lidocaine; D009638:Norepinephrine