PURPOSE: The aim of the present study was to determine whether the eye tissues of arterial hypertensive rats evince expression of angiotensin receptors (AT(1) and AT(2)) as well as the novel Mas receptor, whose endogenous ligand is vasorelaxing Angiotensin (1-7) [Ang (1-7)]. METHODS: Enucleated eyes from spontaneously hypertensive rats (SHR) and double transgenic rats harbouring human renin and angiotensinogen genes (dTGR) and their normotensive controls were used. Half of the rats were pretreated orally with an Angiotensin II (Ang II) type 1 receptor blocker (ARB). The eyes were snap-frozen in isopentane at -40 degrees and stored at -70 degrees for subsequent reverse transcriptase polymerase chain reaction (RT-PCR) analysis or in vitro autoradiography. RESULTS: The mRNA expression of AT(1a) and AT(2) as well as the novel Mas receptor was detected in all rat groups, being markedly higher in the retina than in the ciliary body. dTGR had significantly more receptors than SHR, but no direct relation to blood pressure level was seen. According to the autoradiography, treatment with ARB blocked a part of AT(1) receptors but had no clear effect on AT(2) receptors. CONCLUSION: The novel Mas receptor was found by RT-PCR in eye tissue for the first time. Its specific ligand, Ang (1-7), may be involved in the regulation of intraocular pressure--as recently demonstrated by us--and in the pathogenesis of retinal diseases as a counter-regulatory component for the vascular and proliferative actions of Ang II. The results suggest that the density of AT(1) receptors in the eye is independent of the blood pressure level of the animal.
PURPOSE: The aim of the present study was to determine whether the eye tissues of arterial hypertensiverats evince expression of angiotensin receptors (AT(1) and AT(2)) as well as the novel Mas receptor, whose endogenous ligand is vasorelaxing Angiotensin (1-7) [Ang (1-7)]. METHODS: Enucleated eyes from spontaneously hypertensiverats (SHR) and double transgenic rats harbouring humanrenin and angiotensinogen genes (dTGR) and their normotensive controls were used. Half of the rats were pretreated orally with an Angiotensin II (Ang II) type 1 receptor blocker (ARB). The eyes were snap-frozen in isopentane at -40 degrees and stored at -70 degrees for subsequent reverse transcriptase polymerase chain reaction (RT-PCR) analysis or in vitro autoradiography. RESULTS: The mRNA expression of AT(1a) and AT(2) as well as the novel Mas receptor was detected in all rat groups, being markedly higher in the retina than in the ciliary body. dTGR had significantly more receptors than SHR, but no direct relation to blood pressure level was seen. According to the autoradiography, treatment with ARB blocked a part of AT(1) receptors but had no clear effect on AT(2) receptors. CONCLUSION: The novel Mas receptor was found by RT-PCR in eye tissue for the first time. Its specific ligand, Ang (1-7), may be involved in the regulation of intraocular pressure--as recently demonstrated by us--and in the pathogenesis of retinal diseases as a counter-regulatory component for the vascular and proliferative actions of Ang II. The results suggest that the density of AT(1) receptors in the eye is independent of the blood pressure level of the animal.
Authors: U Muscha Steckelings; Robert E Widdop; Edward D Sturrock; Lizelle Lubbe; Tahir Hussain; Elena Kaschina; Thomas Unger; Anders Hallberg; Robert M Carey; Colin Sumners Journal: Pharmacol Rev Date: 2022-10 Impact factor: 18.923
Authors: Giselle Foureaux; José C Nogueira; Bárbara S Nogueira; Gustavo O Fulgêncio; Gustavo B Menezes; Simone O A Fernandes; Valbert N Cardoso; Renata S Fernandes; Gabriel P Oliveira; Juçara R Franca; André A G Faraco; Mohan K Raizada; Anderson J Ferreira Journal: Invest Ophthalmol Vis Sci Date: 2013-06-21 Impact factor: 4.799
Authors: Giselle Foureaux; Juçara Ribeiro Franca; José Carlos Nogueira; Gustavo de Oliveira Fulgêncio; Tatiana Gomes Ribeiro; Rachel Oliveira Castilho; Maria Irene Yoshida; Leonardo Lima Fuscaldi; Simone Odília Antunes Fernandes; Valbert Nascimento Cardoso; Sebastião Cronemberger; André Augusto Gomes Faraco; Anderson José Ferreira Journal: PLoS One Date: 2015-07-23 Impact factor: 3.240
Authors: G Foureaux; B S Nogueira; D C O Coutinho; M K Raizada; J C Nogueira; A J Ferreira Journal: Braz J Med Biol Res Date: 2015-09-29 Impact factor: 2.590