Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/200820
Type: Artigo de periódico
Title: The Renin-angiotensin System Plays A Major Role In Voiding Dysfunction Of Ovariectomized Rats.
Author: Ramos-Filho, Antonio Celso S
A Faria, Juliana
Calmasini, Fabiano B
Teixeira, Simone A
Mónica, Fabíola Z
Muscará, Marcelo N
Gontijo, José A R
Anhê, Gabriel Forato
Zanesco, Angelina
Antunes, Edson
Abstract: The renin-angiotensin system (RAS) plays a major role in cardiovascular diseases in postmenopausal women, but little is known about its importance to lower urinary tract symptoms. In this study we have used the model of ovariectomized (OVX) estrogen-deficient rats to investigate the role of RAS in functional and molecular alterations in the urethra and bladder. Responses to contractile and relaxant agents in isolated urethra and bladder, as well as cystometry were evaluated in 4-month OVX Sprague-Dawley rats. Angiotensin-converting enzyme activity and Western blotting for AT1/AT2 receptors were examined. Cystometric evaluations in OVX rats showed increases in basal pressure, capacity and micturition frequency, as well as decreased voiding pressure. Angiotensin II and phenylephrine produced greater urethral contractions in OVX compared with Sham group. Carbachol-induced bladder contractions were significantly reduced in OVX group. Relaxations of urethra and bladder to sodium nitroprusside and BAY 41-2272 were unaffected by OVX. Angiotensin-converting enzyme activity was 2.6-fold greater (p<0.05) in urethral tissue of OVX group, whereas enzyme activity in plasma and bladder remained unchanged. Expressions of AT1 and AT2 receptors in the urethra were markedly higher in OVX group. In bladder, AT1 receptors were not detected, whereas AT2 receptor expression was unchanged between groups. 17β-Estradiol replacement (0.1mg/kg, weekly) or losartan (30 mg/kg/day) largely attenuated most of the alterations seen in OVX group. Prolonged estrogen deprivation leads to voiding dysfunction and urethral hypercontractility that are associated with increased ACE activity and up-regulation of angiotensin AT1/AT2 receptor in the urethral tissue.
Subject: Angiotensin Ii
Angiotensin Ii Type 1 Receptor Blockers
Animals
Carbachol
Dose-response Relationship, Drug
Estradiol
Female
In Vitro Techniques
Losartan
Lower Urinary Tract Symptoms
Ovariectomy
Peptidyl-dipeptidase A
Phenylephrine
Pyrazoles
Pyridines
Rats
Rats, Sprague-dawley
Receptor, Angiotensin, Type 1
Receptor, Angiotensin, Type 2
Renin-angiotensin System
Urethra
Urinary Bladder
Urination
Vasoconstrictor Agents
Angiotensin Receptors
Cystometry
Estrogen Replacement Therapy
Losartan
Urethra
Rights: fechado
Identifier DOI: 10.1016/j.lfs.2013.09.008
Address: http://www.ncbi.nlm.nih.gov/pubmed/24050930
Date Issue: 2013
Appears in Collections:Unicamp - Artigos e Outros Documentos

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