BACKGROUND: 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) (ADPbetaS). METHODS: 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 degrees 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. RESULTS: ACh and ADPbetaS-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 ADPbetaS-induced EDR (p<0.05). Moreover, there were no increase in ACh and ADPbetaS-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 ADPbetaS (10-6 M). CONCLUSION: Diabetes induced an endothelium dysfunction. Nevertheless, our intense physical training was not effective to restore the aorta endothelial function.
Zguira, M. S., Vincent, S., Le Douairon Lahaye, S., Malarde, L., Tabka, Z., & Saïag, B. (2013). Intense exercise training is not effective to restore the endothelial NO-dependent relaxation in STZ-diabetic rat aorta. Cardiovascular Diabetology, 12(1). https://doi.org/10.1186/1475-2840-12-32