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 traininginduced 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 (SE) yr] and older (n = 15, 72 ± 1 yr) 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 O2 uptake 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 |
|---|---|
| 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 - Jan 2018 |
Keywords
- Aging
- Exercise hyperemia
- Oxidative metabolism
- PDE5
- Phosphodiesterase 5