Resistance training promotes reduction in Visceral Adiposity without improvements in Cardiomyocyte Contractility and Calcium handling in Obese Rats
Alexandre Barroso Melo, Andressa Prata Leite Damiani, Priscila Murucci Coelho, Arícia Leone Evangelista Monteiro de Assis, Breno Valentim Nogueira, Lucas Guimarães‐Ferreira, Richard Diego Leite, Rogério Faustino Ribeiro Júnior, Ana Paula Lima‐Leopoldo, André Soares Leopoldo
Abstract
Resistance training (RT) improves the cardiomyocyte calcium (Ca 2+ ) cycling during excitation-contraction coupling. However, the role of RT in cardiomyocyte contractile function associated with Ca 2+ handling in obesity is unclear. Wistar rats were distributed into four groups: control, sedentary obese, control plus RT, and obesity plus RT. The 10-wk RT protocol was used (4-5 vertical ladder climbs, 60-second interval, 3 a week, 50-100% of maximum load). Metabolic, hormonal, cardiovascular and biochemical parameters were determined. Reduced leptin levels, epididymal, retroperitoneal and visceral fat pads, lower body fat, and adiposity index were observed in RT. Obesity promoted elevation of collagen, but RT did not promote modifications of LV collagen in ObRT. RT induced elevation in maximum rates of contraction and relaxation, and reduction of time to 50% relaxation. ObRT group did not present improvement in the cardiomyocyte contractile function in comparison to Ob group. Reduced cardiac PLB serine 16 phosphorylation (pPLB Ser 16 ) and pPLB Ser 16 /PLB ratio with no alterations in sarcoplasmic reticulum Ca 2+ ATPase (SERCA2a) and phospholamban (PLB) expression were observed in Ob groups. Resistance training improved body composition reduced fat pads and plasma leptin levels but did not promote positive alterations in cardiomyocyte contractile function, Ca 2+ handling and phospholamban phosphorylation.