清醒犬的盐水诱导性利钠作用及肾血流量：钠输注速率和浓度的影响

Saline-induced natriuresis and renal blood flow in conscious dogs: effects of sodium infusion rate and concentration.

作者信息

Sandgaard N C F, Andersen J L, Holstein-Rathlou N-H, Bie P

机构信息

Department of Physiology and Pharmacology, University of Southern Denmark, Odense, Denmark.

出版信息

Acta Physiol Scand. 2005 Nov;185(3):237-50. doi: 10.1111/j.1365-201X.2005.01480.x.

DOI:10.1111/j.1365-201X.2005.01480.x

PMID:16218929

Abstract

AIM

This study focused on static and dynamic changes in total renal blood flow (RBF) during volume expansion and tested whether a change in RBF characteristics is a necessary effector mechanism in saline-induced natriuresis.

METHODS

The aortic flow subtraction technique was used to measure RBF continuously. Identical amounts of NaCl (2.4 mmol kg(-1)) were given as slow isotonic (Iso, 120 min), slow hypertonic (Hyper, 120 min), and rapid isotonic loads (IsoRapid, 30 min).

RESULTS

During Iso and IsoRapid, arterial blood pressure increased slightly (6-7 mmHg), and during Hyper it remained unchanged. Iso and Hyper increased sodium excretion (4 +/- 1 to 57 +/- 27 and 10 +/- 4 to 79 +/- 28 micromol min(-1), respectively) and decreased plasma renin activity (by 38% and 29%), angiotensin II (by 56% and 58%) and aldosterone (by 47% and 65%), while RBF remained unchanged. IsoRapid caused a similar increase in sodium excretion (to 72 +/- 19 micromol min(-1)), a similar decrease in renin system activity, but a 15% elevation of RBF (282 +/- 22 to 324 +/- 35 mL min(-1)). Selected frequency domain parameters of RBF autoregulation did not change in response to any load.

CONCLUSIONS

In response to slow saline loading simulating daily sodium intake, the rate of sodium excretion may increase 10-20-fold without any change in mean arterial blood pressure or in RBF. Regulatory responses to changes in total body NaCl levels appears, therefore, to be mediated primarily by neurohumoral mechanisms and may occur independent of changes in arterial pressure or RBF.

摘要

目的

本研究聚焦于容量扩张期间肾总血流量（RBF）的静态和动态变化，并测试RBF特征的改变是否为盐水诱导性利钠的必要效应机制。

方法

采用主动脉血流减法技术连续测量RBF。给予相同量的氯化钠（2.4 mmol·kg⁻¹），分别作为慢速等渗（Iso，120分钟）、慢速高渗（Hyper，120分钟）和快速等渗负荷（IsoRapid，30分钟）。

结果

在Iso和IsoRapid期间，动脉血压略有升高（6 - 7 mmHg），而在Hyper期间保持不变。Iso和Hyper增加了钠排泄（分别从4±1增至57±27和从10±4增至79±28 μmol·min⁻¹），并降低了血浆肾素活性（分别降低38%和29%）、血管紧张素II（分别降低56%和58%）以及醛固酮（分别降低47%和65%），而RBF保持不变。IsoRapid导致钠排泄有类似增加（增至72±19 μmol·min⁻¹），肾素系统活性有类似降低，但RBF升高了15%（从282±22增至324±35 mL·min⁻¹）。RBF自动调节的选定频域参数对任何负荷均无变化。