Author |
Barreto, Frederico
![]() Rezende, Daniele Campos ![]() Scaramello, Christianne Bretas Vieira ![]() Silva, Claudia Lucia Martins ![]() Cunha, Valeria do Monti Nascimento ![]() Caricati-Neto, Afonso ![]() ![]() Jurkiewicz, Aron ![]() ![]() Noël, Francois ![]() Quintas, Luis Eduardo Menezes ![]() |
Institution | Universidade Federal do Rio de Janeiro Instituto de Ciências Biomédicas Programa de Farmacologia Universidade Federal Fluminense Instituto Biomédico Departamento de Fisiologia e Farmacologia Universidade Federal de São Paulo (UNIFESP) |
Abstract | The regulatory function of α1B-adrenoceptors in mammalian heart homeostasis is controversial. The objective of the present study was to characterize the expression/activity of key proteins implicated in cardiac calcium handling (Na+/K+-ATPase and Ca2+-ATPases) and growth (ERK1/2, JNK1/2 and p38) in mice with cardiac-selective overexpression of constitutively active mutant α1B-adrenoceptor (CAMα1B-AR), which present a mild cardiac hypertrophy phenotype. Immunoblot assays showed that myocardial plasma membrane Ca2+-ATPase (PMCA) expression was increased by 30% in CAMα1B-AR mice (N = 6, P < 0.05), although there was no change in sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2) expression. Moreover, total Ca2+-ATPase activity was not modified, but a significant increase in the activity of the thapsigargin-resistant (PMCA) to thapsigargin-sensitive (SERCA) ratio was detected. Neither Na+/K+-ATPase activity nor the expression of α1 and α2 subunit isoforms was changed in CAMα1B-AR mouse hearts. Moreover, immunoblot assays did not provide evidence for an enhanced activation of the three mitogen-activated protein kinases studied in this stage of hypertrophy. Therefore, these findings indicate that chronic cardiac α1B-AR activation in vivo led to mild hypertrophy devoid of significant signs of adaptive modifications concerning primary intracellular calcium control and growth-related proteins, suggesting a minor pathophysiological role of this adrenergic receptor in mouse heart at this stage of development. |
Keywords |
α1B-adrenoceptors
Ca2+-ATPases Cardiac hypertrophy Na+/K+-ATPase Mitogen-activated protein kinases |
Language | English |
Sponsor | Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) |
Date | 2010-05-01 |
Published in | Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 43, n. 5, p. 500-505, 2010. |
ISSN | 0100-879X (Sherpa/Romeo, impact factor) |
Publisher | Associação Brasileira de Divulgação Científica |
Extent | 500-505 |
Origin |
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Access rights | Open access ![]() |
Type | Article |
Web of Science ID | WOS:000277830900012 |
SciELO ID | S0100-879X2010000500012 (statistics in SciELO) |
URI | http://repositorio.unifesp.br/handle/11600/5700 |
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