Severe food restriction induces myocardial dysfunction related to SERCA2 activity

Autor(es):Mostrar menos -

Sugizaki, Mario Mateus ^{[1, 2]} ; Leopoldo, Andre Soares ^[1] ; Okoshi, Marina Politi ^[1] ; Bruno, Alessandro ^[1] ; Conde, Sandro Jose ^[1] ; Lima-Leopoldo, Ana Paula ^[1] ; Padovani, Carlos Roberto ^[3] ; Carvalho, Robson Francisco ^[4] ; do Nascimento, Andre Ferreira ^[1] ; Salome de Campos, Dijon Henrique ^[1] ; Nogueira, Celia Regina ^[1] ; Cicogna, Antonio Carlos ^[1]

Afiliação do(s) autor(es)

^[1] UNESP State Univ Julio Mesquita Filho, Sch Med, Dept Clin & Cardiol, Sao Paulo - Brazil

^[2] Fac Integradas Bauru, Dept Phys Educ, FIB, Sao Paulo - Brazil

^[3] UNESP State Univ Julio Mesquita Filho, Dept Biostat, Inst Biol Sci, Sao Paulo - Brazil

^[4] UNESP State Univ Julio Mesquita Filho, Dept Morphol, Inst Biol Sci, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Canadian Journal of Physiology and Pharmacology; v. 87, n. 9, p. 666-673, SEP 2009.
• Citações Web of Science: 5

Resumo

Previous studies have shown that food restriction promotes myocardial dysfunction in rats. However, the molecular mechanisms that are responsible are unclear. We investigated the role of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2) on myocardial performance in food-restricted rats. Male Wistar-Kyoto rats, 60 days old, were fed a control or restricted diet (daily energy intake reduced to 50% of the control) for 90 days. Expression of Serca2a, phospholamban (PLB), Na(+)/Ca(2+) exchanger (NCX), and thyroid hormone receptor (TR alpha 1, TR beta 1) mRNA was determined by quantitative PCR. SERCA2 activity was measured by using 20 mu mol/L cyclopiazonic acid (CPA) in a left ventricular papillary muscle preparation during isometric contraction in basal conditions and during post-rest contraction. Serum concentrations of thyroxine (T(4)) and thyrotropin (TSH) were also determined. The 50%-restricted diet reduced body and ventricular weight and serum T4 and TSH levels. The interaction of CPA and food restriction reduced peak developed tension and maximum rate of tension decline (-dT/dt), but increased the resting tension intensity response during post-rest contraction. PLB and NCX mRNA were upregulated and TR alpha 1 mRNA was downregulated by food restriction. These results suggest that food restriction promotes myocardial dysfunction related to impairment of sarcoplasmic reticulum Ca(2+) uptake as a result of a hypothyroid state. (AU)

• Processo FAPESP: 02/12314-5 - Mecanismos moleculares envolvidos na disfunção miocárdica de ratos submetidos à restrição de ingestão alimentar
• Beneficiário: Antonio Carlos Cicogna
• Modalidade de apoio: Auxílio à Pesquisa - Regular