Exercise training improves blood flow to contracting skeletal muscle of older men via enhanced cGMP signaling

TY - JOUR

T1 - Exercise training improves blood flow to contracting skeletal muscle of older men via enhanced cGMP signaling

AU - Piil, Peter Bergmann

AU - Smith Jørgensen, Tue

AU - Egelund, Jon

AU - Damsgaard, Rasmus

AU - Gliemann, Lasse

AU - Hellsten, Ylva

AU - Nyberg, Michael Permin

N1 - CURIS 2018 NEXS 044

PY - 2018/1

Y1 - 2018/1

N2 - 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.

AB - 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.

KW - Aging

KW - Exercise hyperemia

KW - Oxidative metabolism

KW - PDE5

KW - Phosphodiesterase 5

U2 - 10.1152/japplphysiol.00634.2017

DO - 10.1152/japplphysiol.00634.2017

M3 - Journal article

C2 - 28982945

SN - 8750-7587

VL - 124

SP - 109

EP - 117

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

IS - 1

ER -