| Abstrakt: |
Superoxide (O) overproduction, by decreasing the nitric oxide (NO) bioavailability, contributes to vascular complications in type 1 diabetes. In this disease, the vascular O can be produced by the NADPH oxidase (NOX), nitric oxide synthase (NOS), and xanthine oxidase (XO). This study aimed to determine the contribution of each enzymatic pathway in hyperglycemia-induced O overproduction, and the effects of an endurance training program and insulin therapy, associated or not, on the O production (amount and related enzymes) in diabetic rats. Forty male Wistar rats were divided into diabetic (D), diabetic treated with insulin (D-Ins), diabetic trained (D-Tr), or diabetic insulin-treated and trained (D-Ins + Tr) groups. An additional healthy group was used as control. Insulin therapy (Glargine Lantus, Sanofi) and endurance training (treadmill run: 60 min/day, 25 m/min, 5 days/week) started 1 week after diabetes induction by streptozotocin (45 mg/kg), and lasted for 8 weeks. At the end of the protocol, the O production in aorta rings was evaluated by histochemical analyses (DHE staining). Each production pathway was studied by inhibiting NOX (apocynin), NOS (L-Name), or XO (allopurinol) before DHE staining. Diabetic rats exhibited hyperglycemia-induced O overproduction, resulting from NOX, NOS, and XO activation. Insulin therapy and endurance training, associated or not, decreased efficiently and similarly the O overproduction. Insulin therapy reduced the hyperglycemia and decreased the three enzymatic pathways implicated in the O production. Endurance training decreased directly the NOS and XO activity. While both therapeutic strategies activated different pathways, their association did not reduce the O overproduction more significantly. [ABSTRACT FROM AUTHOR] |
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