Linares O A, Zech L A, Jacquez J A, Rosen S G, Sanfield J A, Morrow L A, Supiano M A, Halter J B
Department of Internal Medicine, University of Michigan Medical School, Ann Arbor.
Am J Physiol. 1988 Feb;254(2 Pt 1):E222-30. doi: 10.1152/ajpendo.1988.254.2.E222.
We used compartmental analysis to analyze the kinetics of distribution and metabolism of norepinephrine (NE) and to determine whether the increase in plasma norepinephrine concentration (PNE) during sodium restriction in humans is due to sympathetic nervous system (SNS) activation. [3H]-NE infusion and postinfusion decay were measured in young subjects in the supine position and during 60 min of standing during normal sodium (NS) diet and after 7 days of 10 meq/day sodium-restricted (SR) diet. The mean supine PNE was greater during SR diet compared with NS diet (154 +/- 9 vs. 185 +/- 12 pg/ml, P = 0.02, n = 10). During both NS and SR diets, upright PNE increased (163 +/- 4 vs. 359 +/- 38 pg/ml and 182 +/- 8 vs. 401 +/- 26 pg/ml, respectively, multivariate one-way analysis of variance, P less than 0.001, alpha = 0.05). The increases of PNE with both SR diet and upright posture were accompanied by a fall in NE metabolic clearance rate (MCR1). During SR diet this was due to a fall in the volume of distribution of NE (6.1 +/- 0.4 vs. 5.0 +/- 0.4 liters, P = 0.003, n = 10). In contrast to the effect of upright posture to increase NE release into the extra-vascular compartment (NE2), during SR diet there was no change in NE2 (1.63 +/- 0.09 vs. 1.62 +/- 0.1 micrograms.min-1.m-2, P = 0.97, n = 10). Thus the increase in PNE during SR diet in humans can be explained by a fall in the volume of distribution of NE, resulting in a decrease in MCR1.(ABSTRACT TRUNCATED AT 250 WORDS)
我们采用房室分析来分析去甲肾上腺素（NE）的分布和代谢动力学，并确定人类限钠期间血浆去甲肾上腺素浓度（PNE）升高是否归因于交感神经系统（SNS）激活。在正常钠（NS）饮食期间及10 mEq/天限钠（SR）饮食7天后，对年轻受试者在仰卧位和站立60分钟期间进行[3H]-NE输注及输注后衰变测量。与NS饮食相比，SR饮食期间平均仰卧位PNE更高（154±9 vs. 185±12 pg/ml，P = 0.02，n = 10）。在NS和SR饮食期间，直立位PNE均升高（分别为163±4 vs. 359±38 pg/ml和182±8 vs. 401±26 pg/ml，多变量单因素方差分析，P<0.001，α = 0.05）。SR饮食和直立位时PNE升高均伴有NE代谢清除率（MCR1）下降。SR饮食期间，这是由于NE分布容积下降（6.1±0.4 vs. 5.0±0.4升，P = 0.003，n = 10）。与直立位增加NE向血管外腔室释放（NE2）的作用相反，SR饮食期间NE2无变化（1.63±0.09 vs. 1.62±0.1微克·分钟-1·米-2，P = 0.97，n = 10）。因此，人类SR饮食期间PNE升高可通过NE分布容积下降来解释，从而导致MCR1降低。（摘要截短于250字）
