Swimming training attenuates contractile dysfunction in diabetic rat cardiomyocytes

• Autor(a) principal: Silva, Márcia Ferreira da
• Data de Publicação: 2010
• Outros Autores: Pelúzio, Maria do Carmo Gouveia, Amorim, Paulo Roberto dos Santos, Lavorato, Vitor Neiva, Santos, Natália Pereira do, Bozi, Luiz Henrique Marchesi, Penitente, Arlete Rita, Falkoski, Daniel Luciano, Berfort, Felipe Gomes, Natali, Antonio Jose
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://dx.doi.org/10.1590/S0066-782X2011005000055; http://www.locus.ufv.br/handle/123456789/12844
• topic: Swimming; Physical exertion; Myocytes; Cardiac; Rats; Diabetes mellitus

Experimental diabetes promotes contractile dysfunction in cardiomyocytes, but the effects of swimming in this disorder are not known. To test the effects of a swimming training program (STP) on cardiomyocyte contractile dysfunction in rats with experimental diabetes. 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). 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. The swimming training program attenuated the contractile dysfunction of the LV myocytes of rats with experimental diabetes.