Exercise Training and Caloric Restriction Prevent Reduction in Cardiac Ca2+-Handling Protein Profile in Obese Rats

Author(s)

Paulino, Ellena Christina ^[1] ; Batista Ferreira, Julio Cesar ^[2] ; Bechara, Luiz Roberto ^[2] ; Tsutsui, Jeane Mike ^[1] ; Mathias, Jr., Wilson ^[1] ; Lima, Fabio Bessa ^[3] ; Casarini, Dulce Elena ^[4] ; Cicogna, Antonio Carlos ^[5] ; Brum, Patricia Chakur ^[2] ; Negrao, Carlos Eduardo ^{[1, 2]}

Affiliation

^[1] Univ Sao Paulo, Sch Med, Inst Heart, InCor, BR-05403900 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Sch Phys Educ & Sport, BR-05403900 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Sch Med, Inst Biomed Sci, BR-05403900 Sao Paulo - Brazil

^[4] Univ Fed Sao Paulo, Div Nephrol, Dept Med, Sao Paulo - Brazil

^[5] Univ Estadual Paulista, Sao Paulo State Univ, Sch Med, Dept Med & Cardiol, Botucatu, SP - Brazil

• Document type: Journal article
• Source: Hypertension; v. 56, n. 4, p. 629-U137, OCT 2010.
• Web of Science Citations: 34

Abstract

Previous studies show that exercise training and caloric restriction improve cardiac function in obesity. However, the molecular mechanisms underlying this effect on cardiac function remain unknown. Thus, we studied the effect of exercise training and/or caloric restriction on cardiac function and Ca2+ handling protein expression in obese rats. To accomplish this goal, male rats fed with a high-fat and sucrose diet for 25 weeks were randomly assigned into 4 groups: high-fat and sucrose diet, high-fat and sucrose diet and exercise training, caloric restriction, and exercise training and caloric restriction. An additional lean group was studied. The study was conducted for 10 weeks. Cardiac function was evaluated by echocardiography and Ca2+ handling protein expression by Western blotting. Our results showed that visceral fat mass, circulating leptin, epinephrine, and norepinephrine levels were higher in rats on the high-fat and sucrose diet compared with the lean rats. Cardiac nitrate levels, reduced/oxidized glutathione, left ventricular fractional shortening, and protein expression of phosphorylated Ser(2808)-ryanodine receptor and Thr(17-)phospholamban were lower in rats on the high-fat and sucrose diet compared with lean rats. Exercise training and/or caloric restriction prevented increases in visceral fat mass, circulating leptin, epinephrine, and norepinephrine levels and prevented reduction in cardiac nitrate levels and reduced: oxidized glutathione ratio. Exercise training and/or caloric restriction prevented reduction in left ventricular fractional shortening and in phosphorylation of the Ser(2808)-ryanodine receptor and Thr(17)-phospholamban. These findings show that exercise training and/or caloric restriction prevent cardiac dysfunction in high-fat and sucrose diet rats, which seems to be attributed to decreased circulating neurohormone levels. In addition, this nonpharmacological paradigm prevents a reduction in the Ser(2808)-ryanodine receptor and Thr(17-)phospholamban phosphorylation and redox status. (Hypertension. 2010;56:629-635.) (AU)

• FAPESP's process: 09/03143-1 - Protein quality control in heart failure: role of different protein kinase C isozymes
• Grantee: Julio Cesar Batista Ferreira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral