Moderate Aerobic Exercise Training Increases Basal Production of Nitric Oxide in Older Women

Abstract

1085 PURPOSE: Vascular endothelial cells produce nitric oxide (NO), which is a potent vasodilator substance and has been proposed as having antiatherosclerotic property. Therefore, NO has been implicated in the regulation of vascular tonus and prevention of progression of atherosclerosis. On the other hand, NO activity reduces with aging. We previously reported that the plasma nitrite/nitrate (NOx: the stable end product of NO) concentration was significantly increased by an intense aerobic exercise training in healthy young humans. We hypothesized that lifestyle modification (e.g., even a moderate regular exercise training) can increase basal NO production in previously sedentary older humans. METHODS: We measured the plasma NOx concentration before and after a moderate aerobic exercise training (cycling on a leg ergometer at 80% ventilatory threshold for 30 min, 5 days/week) for 3 months in ten older women (63 ± 1 years old). Furthermore, we assessed the plasma concentration of cyclic guanosine monophosphate (cGMP), a second messenger of NO, in the same samples. RESULTS: The individual ventilatory threshold significantly increased after the 3-month exercise training. The systolic blood pressure and diastolic blood pressure at rest significantly decreased after the exercise training. These results suggest that the 3-month exercise training in the older women produced favorable physiological effects, i.e., effects of exercise training. The plasma concentration of NOx significantly increased by the exercise training, and the plasma concentration of cGMP also increased by the exercise training. CONCLUSIONS: The present study suggests that even a moderate regular aerobic-endurance exercise increases basal NO production in previously sedentary older humans, which may have beneficial effects (i.e., antihypertensive and antiatherosclerotic effects by endogenous NO) on the cardiovascular system.