ABSTRACT
Objective: During aging, an ineffective perfusion of tissues/organs is a major risk factor for several diseases. Age-induced oxidative stress has been proposed to correlate with this age-related microvascular dysfunction including angiogenesis impairment. It has been demonstrated that exercise training could ameliorate oxidative damage, as well as, enhance angiogenesis in various organs. Therefore, the present study aims to investigate whether exercise training can prevent alterations of capillary vascularity in brain and bone during aging. Design and method: Male Wistar rats were divided into three groups: sedentary-young (aged 4-6 months), sedentary-aged (aged 20-22 months) and train-aged (aged 20-22 months). The exercise program included swimming training 5 days/week for 8 weeks. We directly observed microvasculature of brain and bone by using a laser scanning confocal microscopic system. The microvascular networks were visualized by fluorescein isothiocyanate labeled dextran and were analyzed for capillary vascularity by image analysis software. Blood was collected to determine the level of malondialdehyde, an indicator of oxidative stress. Results: In sedentary-aged group, the malondialdehyde level was significantly increased, whereas capillary vascularities in brain and bone were significantly decreased when compared to the sedentary-young group (P<0.05). In train-aged group, capillary vascularities in brain and bone were significantly higher, whereas the malondialdehyde level was significantly lower when compared to the sedentary-aged group (P<0.05). Besides, the result also showed a linear correlation between capillary vascularity and malondialdehyde level. Conclusion: The exercise training could attenuate age-induced suppression of capillary vascularity in brain and bone, closely related to exercise-ameliorated oxidative stress during aging.