| Full text | |
| Author(s): Show less - |
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]
Total Authors: 12
|
| Affiliation: | [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
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | Canadian Journal of Physiology and Pharmacology; v. 87, n. 9, p. 666-673, SEP 2009. |
| Web of Science Citations: | 5 |
| Abstract | |
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) | |