Intense exercise training is not effective to restore the endothelial NO-dependent relaxation in STZ-diabetic rat aorta
1 Laboratory “Movement Sport and health Sciences”, UFR APS University of Rennes 2, Avenue Charles Tillon, Rennes cedex 35044, France
2 Laboratory “Movement Sport and health Sciences”, ENS Cachan –antenne de Bretagne, Campus Ker Lann, Bruz, France
3 Clinical Laboratory of Physiology, Medical School of Sousse, Sousse, Tunisia
Cardiovascular Diabetology 2013, 12:32 doi:10.1186/1475-2840-12-32Published: 11 February 2013
The aim of this study was to examine the effects of intense physical training on vascular function in streptozotocin-diabetic rats. We focused on the endothelium-dependent relaxation (EDR) induced by acetylcholine (ACh) and stable ADP adenosine-5′- O – (2-thiodiphosphate) (ADPβS).
Control or diabetic male Wistar rats (n=44) were randomly assigned to sedentary or trained groups. The training program consisted in a regular period of running on a treadmill during 8 weeks (10° incline and up to 25 m/min, 60 min/day). The reactivity of isolated thoracic aorta rings of healthy, diabetic and/or trained has been tested.
ACh and ADPβS-induced EDR were observed in phenylephrine (PE) pre-contracted vessels. As compared to sedentary control group, diabetic rats showed an increase in PE-induced contraction and a decrease in ACh and ADPβS-induced EDR (p<0.05). Moreover, there were no increase in ACh and ADPβS-induced EDR in diabetic rats. N-Nitro-L-Arginine Methyl Ester inhibited the nitric oxide synthase in diabetic and control rats, thereby resulting in a strong inhibition of the EDR induced by ACh and ADPβS (10-6 M).
Diabetes induced an endothelium dysfunction. Nevertheless, our intense physical training was not effective to restore the aorta endothelial function.