title: Angiotensin II centrally induces frequent detrusor contractility of the bladder by acting on brain angiotensin II type 1 receptors in rats.
abstract: Angiotensin (Ang) II plays an important role in the brain as a neurotransmitter and is involved in psychological stress reactions, for example through activation of the sympatho-adrenomedullary system. We investigated the effects of centrally administered Ang II on the micturition reflex, which is potentially affected by the sympatho-adrenomedullary system, and brain Ang II receptors in urethane-anesthetized (1.0 g/kg, intraperitoneally) male rats. Central administration of Ang II (0.01, 0.02, and 0.07 nmol per rat, intracerebroventricularly, icv) but not vehicle rapidly and dose-dependently decreased the urinary bladder intercontraction interval, without altering the bladder detrusor pressure. Central administration of antagonists of Ang II type 1 but not type 2 receptors inhibited the Ang II-induced shortening of intercontraction intervals. Administration of the highest dose of Ang II (0.07 nmol per rat, icv) but not lower doses (0.01 and 0.02 nmol per rat, icv) elevated the plasma concentration of adrenaline. Bilateral adrenalectomy reduced Ang II-induced elevation in adrenaline, but had no effect on the Ang II-induced shortening of the intercontraction interval. These data suggest that central administration of Ang II increases urinary frequency by acting on brain Ang II type 1 receptors, independent of activation of the sympatho-adrenomedullary system.
authors.affiliation: Division of Urology, Department of Surgery, Tottori University Faculty of Medicine, Yonago, Japan.
authors.forename: Bunya
authors.initials: B
authors.lastname: Kawamoto
authors.affiliation: Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Shimizu
authors.affiliation: Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Japan.
authors.forename: Youichirou
authors.initials: Y
authors.lastname: Higashi
authors.affiliation: Division of Urology, Department of Surgery, Tottori University Faculty of Medicine, Yonago, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Honda
authors.affiliation: Division of Urology, Department of Surgery, Tottori University Faculty of Medicine, Yonago, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Sejima
authors.affiliation: Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Japan.
authors.forename: Motoaki
authors.initials: M
authors.lastname: Saito
authors.affiliation: Division of Urology, Department of Surgery, Tottori University Faculty of Medicine, Yonago, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takenaka
mesh_terms: D000804:Angiotensin II / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D015415:Biomarkers; D001921:Brain / Q000378:metabolism*; D004837:Epinephrine / Q000097:blood; D008297:Male; D051381:Rats; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism*; D001743:Urinary Bladder / Q000187:drug effects / Q000502:physiology*
chemical_list: D015415:Biomarkers; D044140:Receptor, Angiotensin, Type 1; D000804:Angiotensin II; D004837:Epinephrine