Alpha adrenergic receptor blockade increases capillarisation and fractional O2 extraction and lowers blood flow in contracting human skeletal muscle
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Alpha adrenergic receptor blockade increases capillarisation and fractional O2 extraction and lowers blood flow in contracting human skeletal muscle. / Mortensen, Stefan Peter; Egginton, Stuart; Madsen, Mads; Hansen, Jonas Bo; Munch, Gregers D W; Iepsen, Ulrik Winning; Åkerström, Thorbjörn; Pedersen, Bente Klarlund; Hellsten, Ylva.
I: Acta Physiologica, Bind 221, Nr. 1, 2017, s. 32-43.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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T1 - Alpha adrenergic receptor blockade increases capillarisation and fractional O2 extraction and lowers blood flow in contracting human skeletal muscle
AU - Mortensen, Stefan Peter
AU - Egginton, Stuart
AU - Madsen, Mads
AU - Hansen, Jonas Bo
AU - Munch, Gregers D W
AU - Iepsen, Ulrik Winning
AU - Åkerström, Thorbjörn
AU - Pedersen, Bente Klarlund
AU - Hellsten, Ylva
N1 - CURIS 2017 NEXS 106
PY - 2017
Y1 - 2017
N2 - AIM: To investigate the effect of elevated basal shear stress on angiogenesis in humans, and the role of enhanced skeletal muscle capillarisation on blood flow and O2 extraction.METHODS: Limb haemodynamics and O2 extraction was measured at rest and during one-leg knee-extensor exercise (12 and 24W) in 10 healthy untrained young men before and after 4 weeks treatment with an α1 receptor-antagonist (Terazosin, 1-2 mg day(-1) ). Corresponding biopsies were taken from the m. vastus lateralis.RESULTS: Resting leg blood flow was increased by 57% 6 hours following Terazosin treatment (P<0.05), while basal capillary-to-fibre ratio was 1.69±0.08 and increased to 1.90±0.08 after treatment (P<0.05). Leg O2 extraction during knee-extensor exercise was higher (4-5%; P<0.05), leg blood flow and venous lactate levels lower (6-7%; P<0.05), while leg VO2 was not different after Terazosin treatment.CONCLUSIONS: These results demonstrate that daily treatment with an α-adrenergic receptor blocker induces capillary growth in human skeletal muscle, likely due to increased shear stress. The increase in capillarisation resulted in an increased fractional O2 extraction, a lower blood flow and venous lactate levels in the exercising leg. The increase in capillarisation, and concomitant functional readouts in the exercising leg, may provide a basis for novel angiotherapy. This article is protected by copyright. All rights reserved.
AB - AIM: To investigate the effect of elevated basal shear stress on angiogenesis in humans, and the role of enhanced skeletal muscle capillarisation on blood flow and O2 extraction.METHODS: Limb haemodynamics and O2 extraction was measured at rest and during one-leg knee-extensor exercise (12 and 24W) in 10 healthy untrained young men before and after 4 weeks treatment with an α1 receptor-antagonist (Terazosin, 1-2 mg day(-1) ). Corresponding biopsies were taken from the m. vastus lateralis.RESULTS: Resting leg blood flow was increased by 57% 6 hours following Terazosin treatment (P<0.05), while basal capillary-to-fibre ratio was 1.69±0.08 and increased to 1.90±0.08 after treatment (P<0.05). Leg O2 extraction during knee-extensor exercise was higher (4-5%; P<0.05), leg blood flow and venous lactate levels lower (6-7%; P<0.05), while leg VO2 was not different after Terazosin treatment.CONCLUSIONS: These results demonstrate that daily treatment with an α-adrenergic receptor blocker induces capillary growth in human skeletal muscle, likely due to increased shear stress. The increase in capillarisation resulted in an increased fractional O2 extraction, a lower blood flow and venous lactate levels in the exercising leg. The increase in capillarisation, and concomitant functional readouts in the exercising leg, may provide a basis for novel angiotherapy. This article is protected by copyright. All rights reserved.
KW - Capillarisation
KW - Skeletal muscle
KW - Vasodilatation
U2 - 10.1111/apha.12857
DO - 10.1111/apha.12857
M3 - Journal article
C2 - 28199786
VL - 221
SP - 32
EP - 43
JO - Acta Physiologica
JF - Acta Physiologica
SN - 1748-1708
IS - 1
ER -
ID: 173506276