Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/196362
Type: Artigo de periódico
Title: Effects Of Beta-adrenoceptor Antagonists In The Neural Nitric Oxide Release Induced By Electrical Field Stimulation And Sodium Channel Activators In The Rabbit Corpus Cavernosum.
Author: Teixeira, Cleber E
Baracat, Juliana S
Arantes, Eliane C
De Nucci, Gilberto
Antunes, Edson
Abstract: Beta-Adrenoceptor antagonists may present receptor-independent mechanisms, such as blockade of voltage-gated sodium channels. This study aimed to investigate the effects of non-selective (propranolol), and selective beta1- (atenolol, metoprolol and betaxolol) and beta2-adrenoceptor (ICI 118,551) antagonists in the nitric oxide (NO)-mediated rabbit corpus cavernosum relaxations induced by either electrical field stimulation (EFS) or activators of voltage-gated sodium channels. The sodium channel blockers tetrodotoxin and saxitoxin abolished the relaxations induced by EFS or sodium channel activators of binding site-2 (aconitine and veratridine), site-3 (Ts3 toxin), site-4 (Ts1 toxin) and site-5 (brevetoxin-3). The beta-adrenoceptor antagonists failed to affect the relaxations induced by EFS, aconitine and veratridine. Relaxations induced by Ts3 and Ts1 toxins, as well as brevetoxin-3, were markedly reduced by prior addition of propranolol, betaxolol and ICI 118,551. During the established relaxation induced by Ts3 toxin, propranolol failed to restore the basal tone. In conclusion, beta-adrenoceptor antagonists may cause an allosteric inhibition at the binding site-3, -4 and -5 of voltage-gated sodium channels, leading to blockade of neural NO release.
Subject: Aconitine
Adrenergic Beta-antagonists
Animals
Atenolol
Betaxolol
Binding Sites
Electric Stimulation
In Vitro Techniques
Insect Proteins
Male
Metoprolol
Muscle Relaxation
Neurotoxins
Nitric Oxide
Penis
Propanolamines
Propranolol
Rabbits
Saxitoxin
Scorpion Venoms
Sodium Channel Agonists
Tetrodotoxin
Veratridine
Rights: fechado
Identifier DOI: 10.1016/j.ejphar.2005.07.011
Address: http://www.ncbi.nlm.nih.gov/pubmed/16084509
Date Issue: 2005
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File SizeFormat 
pmed_16084509.pdf171.76 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.