title: Obesity Resistance Promotes Mild Contractile Dysfunction Associated with Intracellular Ca2+ Handling.
abstract: BACKGROUND
  Diet-induced obesity is frequently used to demonstrate cardiac dysfunction. However, some rats, like humans, are susceptible to developing an obesity phenotype, whereas others are resistant to that.
  
  
  OBJECTIVE
  To evaluate the association between obesity resistance and cardiac function, and the impact of obesity resistance on calcium handling.
  
  
  METHODS
  Thirty-day-old male Wistar rats were distributed into two groups, each with 54 animals: control (C; standard diet) and obese (four palatable high-fat diets) for 15 weeks. After the experimental protocol, rats consuming the high-fat diets were classified according to the adiposity index and subdivided into obesity-prone (OP) and obesity-resistant (OR). Nutritional profile, comorbidities, and cardiac remodeling were evaluated. Cardiac function was assessed by papillary muscle evaluation at baseline and after inotropic maneuvers.
  
  
  RESULTS
  The high-fat diets promoted increase in body fat and adiposity index in OP rats compared with C and OR rats. Glucose, lipid, and blood pressure profiles remained unchanged in OR rats. In addition, the total heart weight and the weight of the left and right ventricles in OR rats were lower than those in OP rats, but similar to those in C rats. Baseline cardiac muscle data were similar in all rats, but myocardial responsiveness to a post-rest contraction stimulus was compromised in OP and OR rats compared with C rats.
  
  
  CONCLUSIONS
  Obesity resistance promoted specific changes in the contraction phase without changes in the relaxation phase. This mild abnormality may be related to intracellular Ca2+ handling.
authors.affiliation: Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil.
authors.forename: Felipe Gonçalves Dos Santos de
authors.initials: FG
authors.lastname: Sá
authors.affiliation: Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Lima-Leopoldo
authors.affiliation: Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil.
authors.forename: Bruno Barcellos
authors.initials: BB
authors.lastname: Jacobsen
authors.affiliation: Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil.
authors.forename: Artur Junio Togneri
authors.initials: AJ
authors.lastname: Ferron
authors.affiliation: Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil.
authors.forename: Wagner Muller
authors.initials: WM
authors.lastname: Estevam
authors.affiliation: Departamento de Clínica Médica, Faculdade de Medicina, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil.
authors.forename: Dijon Henrique Salomé
authors.initials: DH
authors.lastname: Campos
authors.affiliation: Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil.
authors.forename: Edson
authors.initials: E
authors.lastname: Castardeli
authors.affiliation: Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil.
authors.forename: Márcia Regina Holanda da
authors.initials: MR
authors.lastname: Cunha
authors.affiliation: Departamento de Clínica Médica, Faculdade de Medicina, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil.
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Cicogna
authors.affiliation: Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil.
authors.forename: André Soares
authors.initials: AS
authors.lastname: Leopoldo
mesh_terms: D050154:Adiposity / Q000502:physiology; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure / Q000502:physiology; D001835:Body Weight; D002118:Calcium / Q000378:metabolism*; D059305:Diet, High-Fat; D004195:Disease Models, Animal; D005951:Glucose Tolerance Test; D007333:Insulin Resistance; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D009765:Obesity / Q000378:metabolism* / Q000503:physiopathology; D009929:Organ Size; D010210:Papillary Muscles / Q000503:physiopathology; D017208:Rats, Wistar; D012016:Reference Values
chemical_list: D001786:Blood Glucose; D002118:Calcium