Systemic α-adrenergic and nitric oxide inhibition on basal limb blood flow:: effects of endurance training in middle-aged and older adults
Systemic α-adrenergic and nitric oxide inhibition on basal limb blood flow:: effects of endurance training in middle-aged and older adults
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DOI：
10.1152/ajpheart.00273.2007
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发表时间：
2007-09-01
影响因子：
4.8
通讯作者：
Tanaka, Hirofumi
中科院分区：
文献类型：
--
作者：
Sugawara, Jun;Komine, Hidehiko;Tanaka, Hirofumi
耐力训练可以改善内皮依赖性血管舒张，但不能增加腿部的基础血流量。我们确定了3个月有氧运动干预对7名明显健康的中年和老年人（60 +/- 3岁）的基础腿部血流量和α-肾上腺素能血管收缩和一氧化氮（NO）释放的影响。基础股动脉血流量（通过多普勒超声）（训练前：354 +/- 29;训练后：335 +/- 34 ml/min）和血管传导性没有随着运动训练而显著改变。在运动干预之前，全身α-肾上腺素能阻滞剂（酚妥拉明）使股动脉血流量增加32 +/- 16%（P < 0.05），并且使用N-G-单甲基-L-精氨酸（L-NMMA）抑制一氧化氮合酶（NOS）对股动脉血流量没有影响。训练完成后，α-肾上腺素能阻滞剂使股动脉血流量增加47 +/- 7%（P < 0.01），随后给予L-NMMA使股动脉血流量减少18 +/- 7%（P < 0.05）。运动干预后，下肢血管传导性显示α-肾上腺素能阻滞诱导的血管舒张（+ 1.7 +/- 0.5至+ 3.0 +/- 0.5单位，P < 0.05）以及NOS抑制诱导的血管收缩（-0.8 +/- 0.4至-2.7 +/- 0.7单位，P < 0.05）更大。静息血浆去甲肾上腺素浓度在训练后显著升高。这些结果表明，有规律的有氧运动训练提高了中老年人的NO生物利用度，并且由于交感神经系统活动和内皮源性血管舒张对血管系统的对比影响，基础肢体血流不会随着运动训练而改变。
Endurance training improves endothelium-dependent vasodilation, yet it does not increase basal blood flow in the legs. We determined the effects of a 3-mo aerobic exercise intervention on basal leg blood flow and alpha-adrenergic vasoconstriction and nitric oxide (NO) release in seven apparently healthy middle-aged and older adults (60 +/- 3 yr). Basal femoral artery blood flow (via Doppler ultrasound) (pretraining: 354 +/- 29; posttraining: 335 +/- 34 ml/min) and vascular conductance did not change significantly with the exercise training. Before the exercise intervention, femoral artery blood flow increased 32 +/- 16% with systemic alpha-adrenergic blockade (with phentolamine) (P < 0.05), and the addition of nitric oxide synthase (NOS) inhibition using N-G-monomethyl-L-arginine (L-NMMA) did not affect femoral artery blood flow. After training was completed, femoral artery blood flow increased 47 +/- 7% with alpha-adrenergic blockade (P < 0.01) and then decreased 18 +/- 7% with the subsequent administration of L-NMMA (P < 0.05). Leg vascular conductance showed a greater alpha-adrenergic blockade-induced vasodilation (+ 1.7 +/- 0.5 to + 3.0 +/- 0.5 units, P < 0.05) as well as NOS inhibition-induced vasoconstriction (-0.8 +/- 0.4 to -2.7 +/- 0.7 units, P < 0.05) after the exercise intervention. Resting plasma norepinephrine concentration significantly increased after the training. These results suggest that regular aerobic exercise training enhances NO bioavailability in middle-aged and older adults and that basal limb blood flow does not change with exercise training because of the contrasting influences of sympathetic nervous system activity and endothelium-derived vasodilation on the vasculature.