TY - JOUR

T1 - Exercise induced capillary growth in human skeletal muscle and the dynamics of VEGF

AU - Høier, Birgitte

AU - Hellsten, Ylva

N1 - CURIS 2014 NEXS 043

PY - 2014

Y1 - 2014

N2 - In skeletal muscle, growth of capillaries is an important adaptation to exercise training that secures adequate diffusion capacity for oxygen and nutrients even at high intensity exercise when increases in muscle blood flow are profound. Mechanical forces present during muscle activity, such as shear stress and passive stretch, lead to cellular signalling, enhanced expression of angiogenic factors and initiation of capillary growth. The most central angiogenic factor in skeletal muscle capillary growth is vascular endothelial growth factor (VEGF). During muscle contraction, VEGF increases in the muscle interstitium, acts on VEGF receptors on the capillary endothelium and thereby stimulates angiogenic processes. A primary source of muscle interstitial VEGF during exercise is the skeletal muscle fibers which contain large stores of VEGF within vesicles. We propose that, during muscle activity, these VEGF containing vesicles are redistributed towards the sarcolemma where the contents are secreted into the extracellular fluid. VEGF mRNA expression is increased primarily after exercise, which allows for a more rapid replenishment of VEGF stores lost through secretion during exercise. Future studies should focus on elucidating mechanisms and regulation of VEGF secretion. This article is protected by copyright. All rights reserved.

AB - In skeletal muscle, growth of capillaries is an important adaptation to exercise training that secures adequate diffusion capacity for oxygen and nutrients even at high intensity exercise when increases in muscle blood flow are profound. Mechanical forces present during muscle activity, such as shear stress and passive stretch, lead to cellular signalling, enhanced expression of angiogenic factors and initiation of capillary growth. The most central angiogenic factor in skeletal muscle capillary growth is vascular endothelial growth factor (VEGF). During muscle contraction, VEGF increases in the muscle interstitium, acts on VEGF receptors on the capillary endothelium and thereby stimulates angiogenic processes. A primary source of muscle interstitial VEGF during exercise is the skeletal muscle fibers which contain large stores of VEGF within vesicles. We propose that, during muscle activity, these VEGF containing vesicles are redistributed towards the sarcolemma where the contents are secreted into the extracellular fluid. VEGF mRNA expression is increased primarily after exercise, which allows for a more rapid replenishment of VEGF stores lost through secretion during exercise. Future studies should focus on elucidating mechanisms and regulation of VEGF secretion. This article is protected by copyright. All rights reserved.

U2 - 10.1111/micc.12117

DO - 10.1111/micc.12117

M3 - Review

C2 - 24450403

VL - 21

SP - 301

EP - 314

JO - Microcirculation

JF - Microcirculation

SN - 1073-9688

IS - 4

ER -