Abstract
Physical activity has the potential to offset age-related impairments in the regulation of blood flow and O2 delivery to the exercising muscles; however, the mechanisms underlying this effect of physical activity remain poorly understood. The present study examined the role of cGMP in training-induced adaptations in the regulation of skeletal muscle blood flow and oxidative metabolism during exercise in aging humans. We measured leg hemodynamics and oxidative metabolism during exercise engaging the knee-extensor muscles in young (n=15, 25 ± 1 years) and older (n=15, 72 ± 1 years) subjects before and after a period of aerobic high-intensity exercise training. To determine the role of cGMP signaling, pharmacological inhibition of phosphodiesterase 5 (PDE5) was performed. Before training, inhibition of PDE5 increased (P<0.05) skeletal muscle blood flow and VO2 during moderate-intensity exercise in the older group; however, these effects of PDE5 inhibition were not detected after training. These findings suggest a role for enhanced cGMP signaling in the training-induced improvement of regulation of blood flow in contracting skeletal muscle of older men.
Original language | English |
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Journal | Journal of Applied Physiology |
Volume | 124 |
Issue number | 1 |
Pages (from-to) | 109-117 |
Number of pages | 9 |
ISSN | 8750-7587 |
DOIs | |
Publication status | Published - 2018 |
Keywords
- Aging
- Exercise hyperemia
- Oxidative metabolism
- PDE5
- Phosphodiesterase 5