Smith D F, Shimizu M
Neuropsychobiology. 1978;4(6):328-32. doi: 10.1159/000117648.
Excretion of lithium in urine was studied in 2 healthy males while recumbent and while upright, either walking or standing quietly. An oral dose of 24.3 mmol of Lit was taken as three lithium carbonate tablets 13 h before clearance tests. Renal lithium clearance decreased and lithium fractional reabsorption increased while upright. Standing immersed to the neck in water, which prevents the fall in plasma volume upon changing posture from recumbent to upright, prevented the fall in renal lithium clearance as well as the rise in lithium fractional reabsorption while upright. Oral doses of guanethidine (total dose of 200 mg) or oxprenolol (total dose of 140 mg) taken to prevent high levels of sympathetic nervous system activity and plasma renin, respectively, failed to prevent the fall in renal lithium clearance or the rise in lithium fractional reabsorption upon changing posture from recumbent to upright. The findings indicate that the fall in renal lithium clearance and the rise in lithium fractional reabsorption upon changing posture from recumbent to upright is related to the fall in plasma volume but not to high levels of sympathetic nervous system activity or plasma renin activity.
对2名健康男性在卧位及立位（安静站立或行走）时的尿锂排泄情况进行了研究。在清除率试验前13小时，口服24.3 mmol锂，以三片碳酸锂的形式服用。立位时肾锂清除率降低，锂分数重吸收增加。站立于颈部浸入水中，这可防止从卧位变为立位时血浆容量下降，同时也防止了立位时肾锂清除率下降以及锂分数重吸收增加。分别口服胍乙啶（总剂量200 mg）或氧烯洛尔（总剂量140 mg）以预防交感神经系统活动增强和血浆肾素水平升高，但未能防止从卧位变为立位时肾锂清除率下降或锂分数重吸收增加。研究结果表明，从卧位变为立位时肾锂清除率下降和锂分数重吸收增加与血浆容量下降有关，而与交感神经系统活动增强或血浆肾素活性升高无关。
