Mas receptor overexpression increased Ang-(1–7) relaxation response in renovascular hypertensive rat carotid

• Published in: Peptides (New York, N.Y. : 1980) Vol. 71; pp. 250 - 258
• Main Authors: Olivon, V.C., Aires, R.D., Santiago, L.B., Ramalho, L.Z.N., Cortes, S.F., Lemos, V.S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.09.2015
• Subjects: Ang-(1– 7); Angiotensin I - metabolism; Animals; Carotid; Carotid Arteries - metabolism; Carotid Arteries - pathology; Carotid Arteries - physiopathology; Gene Expression Regulation; Hypertension - metabolism; Hypertension - pathology; Hypertension - physiopathology; Ibuprofen - pharmacology; Male; Mas receptor; NG-Nitroarginine Methyl Ester - pharmacology; Nitric Oxide - biosynthesis; Nitric Oxide Synthase Type III - biosynthesis; Peptide Fragments - metabolism; Proto-Oncogene Proteins - metabolism; Rats; Rats, Wistar; Receptors, G-Protein-Coupled - metabolism; Renin-Angiotensin System; Renovascular hypertension; Vasodilation; Ang-(1– 7); Mas receptor; Carotid; Renovascular hypertension
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/j.peptides.2015.08.002

•Ang-(1–7)-induced relaxation is increased in carotid artery from hypertensive rats.•The underling mechanism involves enhancement of Mas receptor expression.•Expression and function of eNOS, and NO production are also increased.•Therefore, ang-(1–7) may play a protective role in cerebral circulation. Renin-angiotensin system (RAS) is an important factor in the pathophysiology of hypertension. Mas receptor, Angiotensin-(1–7) [Ang-(1–7)]-activated receptor, is an important RAS component and exerts protective effects in the vasculature. Ang-(1–7) vascular effects and Mas receptor expression in carotid from renovascular hypertensive (2K-1C) rats is not clear. In the present study we investigated Mas receptor vasodilator response activated by Ang-(1–7) in the carotid rings from sham and 2K-1C rats. Changes in isometric tension were recorded on organ chamber. Mas receptors expression was investigated in carotid by Western blot. Nitric oxide production was evaluated by 2,3-diaminonaphthalene (DAN) and eNOS expression and activity by immunofluoresce and western blot, respectively. Ang-(1–7) induced concentration-dependent vasodilator effect in carotid rings from sham and 2K-1C, which the hypertension increased vasodilatation response. In the 2K-1C carotid rings, A-779 (Mas receptor antagonist) reduced but not abolish the vasodilator effect of Ang-(1–7). Corroborating, Mas receptor protein expression was significantly increased in the 2K-1C rats. L-NAME and ibuprofen decreased Ang-(1–7) vasodilator response and L-NAME plus ibuprofen practically abolish the remaining vasodilatation response. Nitric oxide production is increased due increased of eNOS expression and pSer1177 activity. Our results demonstrated that renovascular hypertension increased Mas receptors expression and nitric oxide production in the rats carotid which, consequently increased Ang-(1–7)-vasorelaxant response.