Goldsmith S R, Rector T S, Bank A J, Garr M, Kubo S H
University of Minnesota School of Medicine, Hennepin County Medical Center, Cardiology Division, Minneapolis 55415.
Cardiovasc Res. 1994 May;28(5):663-6. doi: 10.1093/cvr/28.5.663.
The aim was to test the hypothesis that in normal humans angiotensin II would stimulate local release of noradrenaline under basal conditions or during a sympathetic stimulus provided by lower body negative pressure (LBNP).
Nine healthy volunteers received intra-arterial infusions of angiotensin II, 5 ng.min-1, into the non-dominant forearm. Forearm blood flow (strain gauge plethysmography) and regional noradrenaline spillover (using the tracer methodology of Esler) were measured during angiotensin II alone, LBNP alone, and LBNP plus angiotensin II.
Angiotensin II and LBNP decreased forearm blood flow comparably: from 3.1(SD 1.5) to 2.4 (0.9) ml.100 g-1.min-1 during angiotensin II, p < 0.05; and from 3.3(1.5) to 2.5(1.0) ml.100 g-1.min-1 during LBNP, p < 0.05 (p = NS, A-II v LBNP). Angiotensin II had no effect on forearm venous noradrenaline or regional noradrenaline spillover. LBNP increased venous noradrenaline outflow from the forearm, from 1.6(0.40) to 2.1(0.6) nmol.min-1 (p < 0.05), while regional noradrenaline spillover tended to increase, rising from 1.5(0.8) to 2.0(1.0) nmol.100 ml-1.min-1. Angiotensin II did not enhance forearm blood flow or noradrenaline responses to LBNP.
In the human forearm, mildly vasoconstrictor infusions of angiotensin II do not increase local release of noradrenaline, either alone or during mild LBNP. At least under these conditions, angiotensin II would not appear to be a potent influence on local sympathetic activity.
旨在验证以下假设：在正常人体中，血管紧张素II在基础状态下或在下肢负压（LBNP）引起的交感神经刺激期间会刺激去甲肾上腺素的局部释放。
九名健康志愿者在非优势前臂接受5 ng·min⁻¹的血管紧张素II动脉内输注。分别在单独输注血管紧张素II、单独进行LBNP以及LBNP加血管紧张素II的过程中，测量前臂血流量（应变片体积描记法）和局部去甲肾上腺素溢出量（使用埃斯勒的示踪方法）。
血管紧张素II和LBNP对前臂血流量的降低作用相当：血管紧张素II输注期间，血流量从3.1（标准差1.5）降至2.4（0.9）ml·100 g⁻¹·min⁻¹，p < 0.05；LBNP期间，血流量从3.3（1.5）降至2.5（1.0）ml·100 g⁻¹·min⁻¹，p < 0.05（p = 无显著性差异，血管紧张素II与LBNP相比）。血管紧张素II对前臂静脉去甲肾上腺素或局部去甲肾上腺素溢出量无影响。LBNP使前臂静脉去甲肾上腺素流出量增加，从1.6（0.40）增至2.1（0.6）nmol·min⁻¹（p < 0.05），而局部去甲肾上腺素溢出量有增加趋势，从1.5（0.8）升至2.0（1.0）nmol·100 ml⁻¹·min⁻¹。血管紧张素II并未增强前臂血流量或对LBNP的去甲肾上腺素反应。
在人体前臂，轻度血管收缩剂量的血管紧张素II输注，无论是单独使用还是在轻度LBNP期间，均不会增加去甲肾上腺素的局部释放。至少在这些条件下，血管紧张素II似乎对局部交感神经活动没有强大影响。
