代偿期肝硬化患者从仰卧位转为站立位后的肾小管事件：肾小管-肾小球反馈丧失

Renal tubular events following passage from the supine to the standing position in patients with compensated liver cirrhosis: loss of tubuloglomerular feedback.

作者信息

Sansoè G, Biava A M, Silvano S, Ferrari A, Rosina F, Smedile A, Touscoz A, Bonardi L, Rizzetto M

机构信息

Gastroenterology Unit, Gradenigo Hospital, Torino, Italy.

出版信息

Gut. 2002 Nov;51(5):736-41. doi: 10.1136/gut.51.5.736.

DOI:10.1136/gut.51.5.736

PMID:12377816

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1773422/

Abstract

BACKGROUND AND AIMS

Patients with preascitic liver cirrhosis display significant renal sodium retention in the upright posture and an exaggerated natriuresis during recumbency. To date, intrarenal sodium handling in these patients has not been studied using lithium clearance and fractional excretion techniques during recumbency and orthostatism.

METHODS

Ten patients with preascitic (Child-Pugh A) liver cirrhosis and 10 healthy subjects underwent the following measurements during recumbency and then after four hours of standing: (a) active renin and aldosterone plasma levels; and (b) renal clearance of creatinine, sodium, potassium, and lithium (an index of fluid delivery to the loop of Henle).

RESULTS

Unlike the control group, in the upright posture patients had significantly lower values of lithium clearance and fractional excretion compared with recumbency (21.6 (8.6) v 30.5 (10.2) ml/min (p<0.03) and 12.8 (4.4)% v 20.8 (4.9)% (p<0.01), respectively). Our patients showed maintenance of the glomerular-tubular balance-that is, the correlation between creatinine clearance and proximal tubular reabsorption of fluid-during both recumbency and in the upright posture (r=0.96, p<0.001; r=0.97, p<0.001, respectively). In contrast, patients displayed tubuloglomerular feedback only in the supine position. This was demonstrated by the observation of a negative correlation between lithium fractional excretion (a measure of the fractional delivery of sodium to the distal nephron) and filtered sodium load only in recumbency (r=-0.73; p< 0.03) and not during standing (r=0.22; p> 0.05).

CONCLUSIONS

This study suggests that both the reduction in fluid and sodium delivery to the distal nephron and loss of tubuloglomerular feedback (the mechanism increasing glomerular filtration rate when the distal tubule is reached by a reduced sodium load) contribute towards the tendency to sodium retention in compensated cirrhosis during prolonged upright posture.

摘要

背景与目的

腹水前期肝硬化患者在直立位时会出现明显的肾钠潴留，而卧位时则会出现过度利钠。迄今为止，尚未采用锂清除率和分数排泄技术对这些患者在卧位和直立位时的肾内钠处理情况进行研究。

方法

10例腹水前期（Child-Pugh A级）肝硬化患者和10名健康受试者在卧位时以及站立4小时后进行了以下测量：（a）血浆活性肾素和醛固酮水平；（b）肌酐、钠、钾和锂的肾清除率（髓袢液体输送指标）。

结果

与对照组不同，患者在直立位时的锂清除率和分数排泄值显著低于卧位（分别为21.6（8.6）对30.5（10.2）ml/分钟（p<0.03）和12.8（4.4）%对20.8（4.9）%（p<0.01））。我们的患者在卧位和直立位时均维持了球-管平衡，即肌酐清除率与近端肾小管液体重吸收之间的相关性（分别为r=0.96，p<0.001；r=0.97，p<0.001）。相比之下，患者仅在仰卧位时出现管-球反馈。这通过仅在卧位时观察到锂分数排泄（远端肾单位钠分数输送指标）与滤过钠负荷之间呈负相关（r=-0.73；p<0.03），而站立时未观察到（r=0.22；p>0.05）得以证明。