The Role of Angiotensin II on Sodium Appetite After a Low-Sodium Diet

被引:17
|
作者
Mecawi, A. S. [1 ]
Vilhena-Franco, T. [1 ]
Fonseca, F. V. [2 ]
Reis, L. C. [2 ]
Elias, L. L. K. [1 ]
Antunes-Rodrigues, J. [1 ]
机构
[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Physiol, BR-14049900 Sao Paulo, Brazil
[2] Univ Fed Rural Rio de Janeiro, Inst Biol, Dept Physiol Sci, Rio De Janeiro, Brazil
基金
巴西圣保罗研究基金会;
关键词
low-sodium diet; sodium appetite; angiotensin II; AT1; receptors; MESSENGER-RNA LEVELS; SUBFORNICAL ORGAN; INDUCED THIRST; RENIN; RESPONSES; NUCLEUS; SYSTEM; CONNECTIONS; RECEPTORS; RATS;
D O I
10.1111/j.1365-2826.2012.02388.x
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
The present study aimed to investigate the role of angiotensin II (AngII) on sodium appetite in rats subjected to a normal or a low-sodium diet (1% or >0.1% NaCl) for 4days. During sodium restriction, a reduction in water intake, urinary volume and sodium excretion was observed. After a low-sodium diet, we observed decreased plasma protein concentrations and haematocrit associated with a slight reduction in arterial pressure, without any significant changes in heart rate, natraemia, corticotrophin-releasing hormone mRNA expression in the paraventricular nucleus and corticosterone levels. After providing hypertonic saline, there was an increase in saline intake followed by a small increase in water intake, resulting in an enhanced saline intake ratio and the recovery of arterial pressure. Sodium deprivation increased plasma but not brain Ang I and II concentrations. A low-sodium diet increased kidney renin and liver angiotensinogen mRNA levels but not lung angiotensin-converting enzyme mRNA expression. Moreover, Ang II type 1a receptor mRNA expression was increased in the subfornical organ and the dorsal raphe nucleus and decreased in the medial preoptic nuclei, without changes in the paraventricular nucleus and the nucleus of solitary tract after a low-sodium diet. Blockade of AT1 receptors or brain Ang II synthesis led to a reduction in sodium intake after a low-sodium diet. Intracerebroventricular injection of Ang II led to a similar increase in sodium and water intake in the control and low-sodium diet groups. In conclusion, the results of the present study suggest that Ang II is involved in the increased sodium appetite after a low-sodium diet.
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页码:281 / 291
页数:11
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