Abstract 298: Chronic Environmental Enrichment Improves Aging-related Endothelial Dysfunction in Rats: Role of Oxidative Stress

Aging is associated with an endothelial dysfunction, which promotes cardiovascular diseases. Physical exercise has beneficial effects on the endothelial function. However, the effect of an enriched environment (EE) promoting physical exercise, on the endothelial function has not been explored during aging. We investigated the endothelial dysfunction in Long-Evans female rats housed in standard conditions (SD, 2 rats per cage) until the age of 18 months. Then, half the rats were transferred to EE (12 rats in one large cage containing various objects, which were changed 5 times per week) for 6 months. A group of 2-month old rats served as young controls. Systolic (SBP), diastolic (DBP) blood pressure and heart rate (HR) were determined by plethysmography. Vascular reactivity was assessed in mesenteric arteries using organ chambers, vascular oxidative stress by dihydroethidine staining, and the proteins expression by immunofluorescence. Aging under SD was associated with increased SBP (by 40 mmHg, P P P -8 M vs. 3.08 10 -8 M, P max 89.5±11.8% vs. 0.28±0.18%, P max 0.004±0.008 g vs. 0.71±0.07 g, P P P >0.05), and improved NO-mediated responses to a similar level as in young rats ( P P P