Differential regulation of atrial contraction by P1 and P2 purinoceptors in normotensive and spontaneously hypertensive rats

Differential regulation of atrial contraction by P1 and P2 purinoceptors in normotensive and spontaneously hypertensive rats

Author Dantas Rodrigues, Juliano Quintella Autor UNIFESP Google Scholar
Silva, Edilson Dantas da Autor UNIFESP Google Scholar
Galvao, Kleber de Magalhaes Autor UNIFESP Google Scholar
Miranda-Ferreira, Regiane Autor UNIFESP Google Scholar
Caricati-Neto, Afonso Autor UNIFESP Google Scholar
Jurkiewicz, Neide Hyppolito Autor UNIFESP Google Scholar
Garcia, Antonio G. Google Scholar
Jurkiewicz, Aron Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Univ Autonoma Madrid
Abstract In the normotensive rat atrium, adenosine-5'-triphosphate and uridine-5'-triphosphate exert a biphasic effect consisting of an initial negative inotropic effect (NIE) followed by a subsequent positive inotropic effect (PIE). We comparatively studied these responses in normotensive Wistar rats (NWRs) and spontaneously hypertensive rats (SHRs). Compared with NWRs, the NIE responses in the atria were lower and the PIE responses were higher in SHRs. the P1 purinoceptor antagonist, D 8-cyclopentyl-1,3- dipropylxanthine, partially blocked the NIE responses of both ATP and UTP and mildly enhanced the PIE responses in both NWRs and SHRs. Furthermore, the P2 purinoceptor blockers suramin and pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid tetrasodium salt induced a pronounced block of the PIE responses in both atria types. the PIE responses to ATP were inhibited more efficiently by nifedipine. These responses were depressed by ryanodine and, to a lesser extent, carbonyl cyanide 3-chlorophenylhydrazone in SHR atria compared with NWR atria. the higher responses in SHR rats suggest the existence of an augmented endoplasmic reticulum Ca2+ store and faster mitochondrial Ca2+ cycling in SHR atria compared with NWR atria. These data support the hypothesis that a dysfunction of purinergic neurotransmission and enhanced sympathetic activity are contributing factors in the pathogenesis of hypertension.
Keywords hypertension
isolated left atrium
P1 and P2 purinergic receptors
Language English
Sponsor Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Date 2014-03-01
Published in Hypertension Research. London: Nature Publishing Group, v. 37, n. 3, p. 210-219, 2014.
ISSN 0916-9636 (Sherpa/Romeo, impact factor)
Publisher Nature Publishing Group
Extent 210-219
Origin http://dx.doi.org/10.1038/hr.2013.146
Access rights Closed access
Type Article
Web of Science ID WOS:000332451200004
URI http://repositorio.unifesp.br/handle/11600/37505

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