Nitric oxide synthase inhibition does not affect regulation of muscle sympathetic nerve activity during head-up tilt.
Nitric oxide synthase inhibition does not affect regulation of muscle sympathetic nerve activity during head-up tilt.
复制标题
一氧化氮合酶抑制不会影响抬头倾斜期间肌肉交感神经活动的调节。
DOI：
10.1152/ajpheart.01076.2002
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Levine,BenjaminD
中科院分区：
文献类型：
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作者：
Cui,Jian;Zhang,Rong;Wilson,ThadE;Witkowski,Sarah;Crandall,CraigG;Levine,BenjaminD
为了验证一氧化氮（NO）合酶的全身抑制不会改变人类直立倾斜期间交感神经流出的调节这一假设，在8名健康受试者中，通过静脉输注NG-单甲基-L-精氨酸（L-NMMA）阻断NO合酶。记录仰卧位和头高位60°时的血压、心率、心输出量、总外周阻力（TPR）和肌肉交感神经活动（MSNA）。在仰卧位，输注的fl-NMMA增加血压，通过增加TPR，并抑制MSNA。然而，在l-NMMA输注期间由头高位倾斜诱发的MSNA增加（爆发速率变化：24 ± 4爆发/min;总活动变化：209 ± 36 U/min）与在无l-NMMA的头高位倾斜期间相似（爆发速率变化：23 ± 4爆发/min;总活动变化：251 ± 52 U/min，n= 6，均P> 0.05）。此外，TPR和心率在头向上倾斜期间的变化在两种情况下几乎相同。这些结果表明，全身抑制NO合酶与l-NMMA不影响调节交感神经流出和血管阻力在头向上倾斜在人类。
To test the hypothesis that systemic inhibition of nitric oxide (NO) synthase does not alter the regulation of sympathetic outflow during head-up tilt in humans, in eight healthy subjects NO synthase was blocked by intravenous infusion ofNG-monomethyl-l-arginine (l-NMMA). Blood pressure, heart rate, cardiac output, total peripheral resistance (TPR), and muscle sympathetic nerve activity (MSNA) were recorded in the supine position and during 60° head-up tilt. In the supine position, infusion ofl-NMMA increased blood pressure, via increased TPR, and inhibited MSNA. However, the increase in MSNA evoked by head-up tilt duringl-NMMA infusion (change in burst rate: 24 ± 4 bursts/min; change in total activity: 209 ± 36 U/min) was similar to that during head-up tilt withoutl-NMMA (change in burst rate: 23 ± 4 bursts/min; change in total activity: 251 ± 52 U/min,n= 6, allP> 0.05). Moreover, changes in TPR and heart rate during head-up tilt were virtually identical between the two conditions. These results suggest that systemic inhibition of NO synthase withl-NMMA does not affect the regulation of sympathetic outflow and vascular resistance during head-up tilt in humans.