title: Swimming training attenuates contractile dysfunction in diabetic rat cardiomyocytes.
abstract: BACKGROUND
  Experimental diabetes promotes contractile dysfunction in cardiomyocytes, but the effects of swimming in this disorder are not known.
  
  
  OBJECTIVE
  To test the effects of a swimming training program (STP) on cardiomyocyte contractile dysfunction in rats with experimental diabetes.
  
  
  METHODS
  Wistar rats (age: 30 days; mean body weight: 84.19 g) with diabetes induced by streptozotocin (60 mg/kg body weight; glucose > 300 mg/dl) were divided into sedentary diabetic rats (SD, n = 10) and exercised diabetic rats (ED, n = 13). Animals of same age and weight served as sedentary controls (SC, n = 10) and exercised controls (EC, n = 06). Animals and ED and EC underwent a STP (05 days/week, 90 min/day) for 08 weeks. Left ventricular (LV) myocytes were isolated and electrically stimulated at 3.0 Hz at room temperature (∼ 25º C).
  
  
  RESULTS
  Diabetes reduced contractile function in cardiomyocytes of animals compared to controls (i.e., lower amplitude of contraction, longer duration of contraction and relaxation). The STP attenuated the reduced amplitude of contraction (SC, 11 ± 0.2% vs ED, 11.6 ± 0.2%), time to peak contraction (SC, 319 ± 5.8 ms vs ED, 333 ± 4.8 ms) and time to 50.0% of relaxation (SC, 619 ± 22.2 ms vs ED 698 ± 18.6 ms) of cardiomyocytes of diabetic rats. Diabetes reduced the size of cardiomyocytes, however, the STP minimized the reduction of cell volume and width, without changing length.
  
  
  CONCLUSIONS
  The swimming training program attenuated the contractile dysfunction of the LV myocytes of rats with experimental diabetes.
authors.affiliation: Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors.forename: Márcia Ferreira da
authors.initials: MF
authors.lastname: Silva
authors.forename: Maria do Carmo Gouveia
authors.initials: Mdo C
authors.lastname: Pelúzio
authors.forename: Paulo Roberto dos Santos
authors.initials: PR
authors.lastname: Amorim
authors.forename: Vitor Neiva
authors.initials: VN
authors.lastname: Lavorato
authors.forename: Natália Pereira do
authors.initials: NP
authors.lastname: Santos
authors.forename: Luiz Henrique Marchesi
authors.initials: LH
authors.lastname: Bozi
authors.forename: Arlete Rita
authors.initials: AR
authors.lastname: Penitente
authors.forename: Daniel Luciano
authors.initials: DL
authors.lastname: Falkoski
authors.forename: Felipe Gomes
authors.initials: FG
authors.lastname: Berfort
authors.forename: Antonio Jose
authors.initials: AJ
authors.lastname: Natali
mesh_terms: D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D009200:Myocardial Contraction / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013550:Swimming / Q000502:physiology*; D013997:Time Factors; D016277:Ventricular Function, Left / Q000502:physiology