title: Role of angiotensin-(1-7) in rostral ventrolateral medulla in blood pressure regulation via sympathetic nerve activity in Wistar-Kyoto and spontaneous hypertensive rats.
abstract: Angiotensin (Ang)-(1-7) Ang-(1-7) is formed from angiotensin II by angiotensin-converting enzyme 2 (ACE2) and modulates the renin-angiotensin system. We evaluated whether the Ang-(1-7)-Mas axis in the rostral ventrolateral medulla (RVLM) contributes to neural mechanisms of blood pressure (BP) regulation. We microinjected Ang-(1-7), Ang-(1-7)-Mas receptor antagonist A-779, and ACE2 inhibitor DX600 into the RVLM of anesthetized Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHRs). Unilateral Ang-(1-7) microinjection induced a significantly greater increase in AP (arterial blood pressure) in SHR than in WKY. Bilateral A-779 microinjection induced a significantly greater decrease in AP and renal sympathetic nerve activity in SHR than in WKY. Bilateral DX600 microinjection induced a significantly greater decrease in AP in SHR than in WKY. Our results suggest that endogenous Ang-(1-7) in the RVLM contributes to maintain AP and renal sympathetic nerve activity both in SHR and WKY and that its activity might be enhanced in SHR.
authors.affiliation: Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Nakagaki
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Hirooka
authors.forename: Koji
authors.initials: K
authors.lastname: Ito
authors.forename: Takuya
authors.initials: T
authors.lastname: Kishi
authors.forename: Sumio
authors.initials: S
authors.lastname: Hoka
authors.forename: Kenji
authors.initials: K
authors.lastname: Sunagawa
mesh_terms: D000803:Angiotensin I / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology*; D000804:Angiotensin II / Q000031:analogs & derivatives / Q000494:pharmacology; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D004195:Disease Models, Animal; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008526:Medulla Oblongata / Q000502:physiology*; D008845:Microinjections; D010446:Peptide Fragments / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology*; D010455:Peptides / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology*; D013777:Tetrazoles / Q000494:pharmacology; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology; D000068756:Valsartan
chemical_list: C092006:7-Ala-angiotensin (1-7); D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; C556151:DX600 peptide; D010446:Peptide Fragments; D010455:Peptides; D013777:Tetrazoles; D000804:Angiotensin II; D000068756:Valsartan; D000803:Angiotensin I; D014633:Valine; C118790:angiotensin I (1-7)