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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Functional beta(2)-adrenoceptors in rat left atria: effect of foot-shock stress

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Autor(es):
de Moura, Andre Luiz ; Hyslop, Stephen ; Grassi-Kassisse, Dora M. ; Spadari, Regina C.
Número total de Autores: 4
Tipo de documento: Artigo Científico
Fonte: Canadian Journal of Physiology and Pharmacology; v. 95, n. 9, p. 999-1008, SEP 2017.
Citações Web of Science: 2
Resumo

Altered sensitivity to the chronotropic effect of catecholamines and a reduction in the beta(1)/beta(2)-adrenoceptor ratio have previously been reported in right atria of stressed rats, human failing heart, and aging. In this report, we investigated whether left atrial inotropism was affected by foot-shock stress. Male rats were submitted to 3 foot-shock sessions and the left atrial inotropic response, adenylyl cyclase activity, and beta-adrenoceptor expression were investigated. Left atria of stressed rats were supersensitive to isoprenaline when compared with control rats and this effect was abolished by ICI118,551, a selective beta(2)-receptor antagonist. Schild plot slopes for the antagonism between CGP20712A (a selective beta(1)-receptor antagonist) and isoprenaline differed from unity in atria of stressed but not control rats. Atrial sensitivity to norepinephrine, as well as basal and forskolin-or isoprenaline-stimulated adenylyl cyclase activities were not altered by stress. The effect of isoprenaline on adenylyl cyclase stimulation was partially blocked by ICI118,551 in atrial membranes of stressed rats. These findings indicate that foot-shock stress equally affects inotropism and chronotropism and that beta(2)-adrenoceptor upregulation contributes to the enhanced inotropic response to isoprenaline. (AU)

Processo FAPESP: 00/03719-6 - Sensibilidade a agonistas beta-adrenérgicos em átrio esquerdo isolado de ratos submetidos a estresse
Beneficiário:André Luiz de Moura
Modalidade de apoio: Bolsas no Brasil - Mestrado