The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.
Acta Physiol (Oxf). 2017 Sep;221(1):32-43. doi: 10.1111/apha.12857. Epub 2017 Apr 11.
To assess the effect of elevated basal shear stress on angiogenesis in humans and the role of enhanced skeletal muscle capillarization on blood flow and O extraction.
Limb haemodynamics and O extraction were measured at rest and during one-leg knee-extensor exercise (12 and 24 W) in 10 healthy untrained young men before and after 4-week treatment with an α receptor-antagonist (Terazosin, 1-2 mg day ). Corresponding biopsies were taken from the m. vastus lateralis.
Resting leg blood flow was increased by 57% 6 h 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 O 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 VO was not different after Terazosin treatment.
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 capillarization resulted in an increased fractional O extraction, a lower blood flow and venous lactate levels in the exercising leg. The increase in capillarization, and concomitant functional readouts in the exercising leg, may provide a basis for novel angiotherapy.
评估基础切应力升高对人类血管生成的影响，以及增强骨骼肌毛细血管化对血流和 O 摄取的作用。
在 10 名健康未训练的年轻男性中，在双腿伸膝运动（12 和 24 W）期间和休息时测量肢体血液动力学和 O 摄取，然后在接受为期 4 周的α受体拮抗剂（特拉唑嗪，1-2 mg/天）治疗前后。从股外侧肌采集相应的活检样本。
在特拉唑嗪治疗后 6 小时，休息时腿部血流量增加了 57%（P < 0.05），而基础毛细血管与纤维比为 1.69 ± 0.08，并增加到治疗后的 1.90 ± 0.08（P < 0.05）。伸膝运动期间腿部 O 摄取更高（4-5%；P < 0.05），腿部血流量和静脉乳酸水平更低（6-7%；P < 0.05），而在接受特拉唑嗪治疗后腿部 VO 没有差异。
这些结果表明，每天使用α肾上腺素能受体阻滞剂治疗会导致人体骨骼肌毛细血管生长，可能是由于切应力增加所致。毛细血管化的增加导致运动腿部的分数 O 摄取增加、血流量和静脉乳酸水平降低。毛细血管化的增加以及运动腿部的伴随功能指标可能为新的血管生成治疗提供基础。
