title: Angiotensin II acting on brain AT1 receptors induces adrenaline secretion and pressor responses in the rat.
abstract: Angiotensin II (AngII) plays important roles in the regulation of cardiovascular function. Both peripheral and central actions of AngII are involved in this regulation, but mechanisms of the latter actions as a neurotransmitter/neuromodulator within the brain are still unclear. Here we show that (1) intracerebroventricularly (i.c.v.) administered AngII in urethane-anesthetized male rats elevates plasma adrenaline derived from the adrenal medulla but not noradrenaline with valsartan- (AT1 receptor blocker) sensitive brain mechanisms, (2) peripheral AT1 receptors are not involved in the AngII-induced elevation of plasma adrenaline, although AngII induces both noradrenaline and adrenaline secretion from bovine adrenal medulla cells, and (3) i.c.v. administered AngII elevates blood pressure but not heart rate with the valsartan-sensitive mechanisms. From these results, i.c.v. administered AngII acts on brain AT1 receptors, thereby inducing the secretion of adrenaline and pressor responses. We propose that the central angiotensinergic system can activate central adrenomedullary outflow and modulate blood pressure.
authors.affiliation: Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Department of Pharmacology, University of Miyazaki, Faculty of Medicine, Miyazaki 889-1692, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Yanagita
authors.affiliation: Department of Pharmacology, University of Miyazaki, Faculty of Medicine, Miyazaki 889-1692, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nemoto
authors.affiliation: Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Taniuchi
authors.affiliation: Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Shimizu
authors.affiliation: B' Urologic Department, Papageorgiou General Hospital, Aristotle University School of Medicine, Thessaloniki, Greece.
authors.forename: Fotios
authors.initials: F
authors.lastname: Dimitriadis
authors.affiliation: Department of Neurosurgery, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Yawata
authors.affiliation: Department of Neurosurgery, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan.
authors.forename: Youichirou
authors.initials: Y
authors.lastname: Higashi
authors.affiliation: Department of Neurosurgery, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ueba
authors.affiliation: Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan.
authors.forename: Motoaki
authors.initials: M
authors.lastname: Saito
mesh_terms: D000313:Adrenal Medulla / Q000187:drug effects / Q000378:metabolism; D000804:Angiotensin II / Q000494:pharmacology*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D004837:Epinephrine / Q000378:metabolism*; D007276:Injections, Intraventricular / Q000379:methods; D008297:Male; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism*; D013777:Tetrazoles / Q000494:pharmacology; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology; D000068756:Valsartan
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D044140:Receptor, Angiotensin, Type 1; D013777:Tetrazoles; D000804:Angiotensin II; D000068756:Valsartan; D014633:Valine; D009638:Norepinephrine; D004837:Epinephrine