Abstract
BackgroundInformations about the effects of intense exercise training on diabetes-induced myocardial dysfunctions are lacking. We have examined the effects of intense exercise training on the cardiac function of diabetic rats, especially focusing on the Langendorff β-adrenergic responsiveness and on the β-adrenoceptors protein expression.MethodsControl or Streptozotocin induced-diabetic male Wistar rats were randomly assigned to sedentary or trained groups. The training program consisted of 8 weeks running on a treadmill (10° incline, up to 25 m/min, 60 min/day) and was considered to be intense for diabetic rats.ResultsThis intense exercise training amplified the in vivo diabetes-induced bradycardia. It had no effect on Langendorff basal cardiac contraction and relaxation performances in control and diabetic rats. In diabetic rats, it accentuated the Langendorff reduced responsiveness to β-adrenergic stimulation. It did not blunt the diabetes-induced decrease of β1-adrenoceptors protein expression, displayed a significant decrease in the β2-adrenoceptors protein expression and normalized the β3-adrenoceptors protein expression.ConclusionsIntense exercise training accentuated the decrease in the myocardial responsiveness to β-adrenergic stimulation induced by diabetes. This defect stems principally from the β2-adrenoceptors protein expression reduction. Thus, these results demonstrate that intense exercise training induces specific effects on the β-adrenergic system in diabetes.
Highlights
Informations about the effects of intense exercise training on diabetes-induced myocardial dysfunctions are lacking
In a preliminary study [17], we demonstrated that 8 weeks of intense exercise training has specific and opposite effects to those obtained with more moderate exercise training [3] on b2-adrenoceptors expression in diabetic rat hearts
Training reduced the levels of blood glucose, which was lower in trained diabetic rats than in their sedentary counterparts (p
Summary
Informations about the effects of intense exercise training on diabetes-induced myocardial dysfunctions are lacking. In a preliminary study [17], we demonstrated that 8 weeks of intense exercise training has specific and opposite effects to those obtained with more moderate exercise training [3] on b2-adrenoceptors expression in diabetic rat hearts. Intense exercise training during diabetes decreases cardiac b2-adrenoceptors expression Based on these data and others in different experimental models (healthy rats, obese rabbits...), we hypothesized that exercise training may affect differently all of the above mentioned factors depending on the load [18,19]. The present study was conducted to investigate the effect of 8 weeks of intense exercise training on both cardiac function and b-adrenergic system in diabetic rat hearts
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
