title: Swimming training attenuates the morphological reorganization of the myocardium and local inflammation in the left ventricle of growing rats with untreated experimental diabetes.
abstract: Diabetic cardiomyopathy is associated with cardiac remodeling, myocardial dysfunction, low-grade inflammation, and reduced cardiac adiponectin in patients with type 1 diabetes mellitus (T1DM). Alternatively, physical exercise is an important strategy for the management of diabetes. This study aimed to investigate the influence of low-intensity swimming training in cardiac cytokines, structural remodeling, and cardiomyocyte contractile dysfunction in growing rats with untreated experimental DM. Thirty-day-old male Wistar rats were divided into four groups (n=14, per group): sedentary control (SC), exercised control (EC), sedentary diabetic (SD), and exercised diabetic (ED). Diabetes was induced by streptozotocin (60 mg kg(-1), i.p.). Animals from exercised groups swam (5 days/week, 90 min/day, loading up to 5% body weight around the animal's chest) for 8 weeks. The left ventricle (LV) was removed for molecular, morphological, and cardiomyocyte mechanical analysis. Diabetic animals presented cardiac remodeling with myocardial histoarchitectural disorganization, fibrosis, and necrosis. The capillary density was lower in diabetic animals. LV cardiomyocytes from diabetic animals exhibited more prolonged time to the peak of contraction and time to half relaxation than those from control animals. The cardiac levels of interleukin 10, nitric oxide, and total and high molecular weight (HMW) adiponectin were significantly decreased in diabetic animals. Exercise training reduced the level of TNF-α, increased capillary density, and attenuated the histopathological parameters assessed in diabetic rats. In conclusion, the cardiac structural remodeling coexists with reduced levels of total and HMW adiponectin, inflammation, and cardiomyocyte contractility dysfunction in experimental DM. More important, low-intensity swimming training attenuates part of these pathological changes, indicating the beneficial role for exercise in untreated T1DM.
authors.affiliation: Department of General Biology, Federal University of Viçosa, Viçosa, MG, Brazil; Department of Basic Sciences, Federal University of Jequitinhonha and Mucuri Valleys, Diamantina, MG, Brazil. Electronic address: edsondasilvaatm@hotmail.com.
authors.forename: Edson
authors.initials: E
authors.lastname: da Silva
authors.affiliation: Department of Physical Education, Federal University of Viçosa, Viçosa, MG, Brazil.
authors.forename: Antônio José
authors.initials: AJ
authors.lastname: Natali
authors.affiliation: Department of General Biology, Federal University of Viçosa, Viçosa, MG, Brazil.
authors.forename: Márcia Ferreira
authors.initials: MF
authors.lastname: da Silva
authors.affiliation: Department of Physical Education, Federal University of Viçosa, Viçosa, MG, Brazil; Department of Physical Education, Federal University of Jequitinhonha and Mucuri Valleys, Diamantina, MG, Brazil.
authors.forename: Gilton de Jesus
authors.initials: Gde J
authors.lastname: Gomes
authors.affiliation: Department of Physical Education, Federal University of Viçosa, Viçosa, MG, Brazil.
authors.forename: Daise Nunes Queiroz
authors.initials: DN
authors.lastname: da Cunha
authors.affiliation: Department of Medicine and Nursing, Federal University of Viçosa, Viçosa, MG, Brazil.
authors.forename: Marileila Marques
authors.initials: MM
authors.lastname: Toledo
authors.affiliation: Department of Physical Education, Federal University of Viçosa, Viçosa, MG, Brazil.
authors.forename: Filipe Rios
authors.initials: FR
authors.lastname: Drummond
authors.affiliation: Department of Physical Education, Federal University of Viçosa, Viçosa, MG, Brazil.
authors.forename: Regiane Maria Soares
authors.initials: RM
authors.lastname: Ramos
authors.affiliation: Department of General Biology, Federal University of Viçosa, Viçosa, MG, Brazil; Faculty of Medicine, Federal University of Jequitinhonha and Mucuri Valleys, Diamantina, MG, Brazil.
authors.forename: Eliziária Cardoso
authors.initials: EC
authors.lastname: Dos Santos
authors.affiliation: Department of General Biology, Federal University of Viçosa, Viçosa, MG, Brazil; Biomedical Sciences Institute, Federal University of Alfenas, MG, Brazil.
authors.forename: Rômulo Dias
authors.initials: RD
authors.lastname: Novaes
authors.affiliation: Department of General Biology, Federal University of Viçosa, Viçosa, MG, Brazil.
authors.forename: Leandro Licursi
authors.initials: LL
authors.lastname: de Oliveira
authors.affiliation: Department of General Biology, Federal University of Viçosa, Viçosa, MG, Brazil.
authors.forename: Izabel Regina dos Santos Costa
authors.initials: IR
authors.lastname: Maldonado
mesh_terms: D000818:Animals; D003921:Diabetes Mellitus, Experimental; D058065:Diabetic Cardiomyopathies / Q000473:pathology* / Q000503:physiopathology / Q000534:rehabilitation*; D004562:Electrocardiography; D004797:Enzyme-Linked Immunosorbent Assay; D006352:Heart Ventricles / Q000473:pathology* / Q000503:physiopathology; D007150:Immunohistochemistry; D007249:Inflammation / Q000473:pathology; D008297:Male; D009206:Myocardium / Q000473:pathology*; D032383:Myocytes, Cardiac / Q000473:pathology; D010805:Physical Conditioning, Animal / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D013550:Swimming
keywords: Adiponectin; Cardiomyocyte; Diabetes mellitus; Exercise; Inflammation; Ventricular remodeling