title: Angiotensin II reduces serotonin release in the rat subfornical organ area.
abstract: In the present study we used intracerebral microdialysis techniques to examine whether angiotensin II (ANG II) modulates the release of serotonin (5-hydroxytryptamine, 5-HT) in the subfornical organ (SFO) in freely moving rats. Extracellular concentrations of 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the region of the SFO were significantly decreased by microinjection of ANG II (10 pmol, 50 nl), but not by vehicle, into the dialysis site. No significant changes in the 5-HT and 5-HIAA levels caused by ANG II were observed in the sites away from the SFO. Water ingestion significantly enhanced the amount of the decrease in the 5-HT and 5-HIAA concentrations in the SFO area elicited by the ANG II injection. These results show that ANG II may reduce the release of 5-HT in the SFO area, and imply that the 5-HT receptor mechanism in the SFO area may participate in the elicitation of the drinking behavior to ANG II.
authors.affiliation: Department of Curriculum, Teaching and Memory, Naruto University of Education, Naruto, Tokushima 772-8502, Japan. tanakaj@naruto-u.ac.jp
authors.forename: Junichi
authors.initials: J
authors.lastname: Tanaka
authors.forename: Katsuhide
authors.initials: K
authors.lastname: Kariya
authors.forename: Masahiko
authors.initials: M
authors.lastname: Nomura
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D004326:Drinking / Q000187:drug effects; D004789:Enzyme Activation; D006897:Hydroxyindoleacetic Acid / Q000032:analysis; D008297:Male; D017551:Microdialysis; D008845:Microinjections; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*; D013356:Subfornical Organ / Q000187:drug effects* / Q000378:metabolism*; D014867:Water
chemical_list: D014867:Water; D000804:Angiotensin II; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid