semmelweis university - Faculty of Physical Education and Sport ...

Le Douairon Lahaye S. 1 ,-Malardé S. 1 ,-Zguira MS. 1 ,-Rebillard A. 1 ,-Vincent S. 1 ,-Lemoine
Morel S. 1 ,-Delamarche P. 1 ,-Carré F. 2 ,-Rannou Bekono F. 1
1
Laboratory Movement, Sport and Health Sciences, Rennes 2 University - ENS Cachan,
France
2
INSERM, U642, Rennes 1 University, France
Combined Effects of Type 1 Diabetes and Exercise Training on Cardiac Function: Study
of Nos1, Ryr2 and Β3-Adrenoceptor
Introduction: In diabetic cardiomyopathy, β3-adrenoceptor (β3-AR) overexpression plays an
important role in the altered response to β-adrenergic stimulation via induction of neuronal
nitric oxide synthase (NOS1)-derived nitric oxide. Moreover, the diabetes-induced
upregulation of NOS1 could decrease cardiac function via NOS1-translocation and
consequently, hyponitrosylation of the cardiac Ca2+ release channel ryanodine receptor
(RyR2). We hypothesised that exercise training might improve cardiac function during
diabetes by affecting β3-AR, NOS1 and RyR2.
Methods: 46 male Wistar rats were randomly assigned into a diabetic group receiving no
treatment (D), an insulin-treated diabetic (Ins), a trained diabetic (TD), and a trained insulintreated
diabetic (TIns) groups. Control group (C) was included in order to confirm the
negative effects of diabetes. Insulin treatment and/or treadmill exercise training were
conducted during 8 weeks. Cardiac function was evaluated by Langendorff technique. Protein
expression of β3-AR, NOS1 and RyR2 was assessed using Western blots.
Results: Diabetes induced a decrease of both diastolic (-dP/dt) and systolic (+dP/dt) cardiac
function evaluated by Langendorff technique (p