Sodium balance, arterial pressure, and the role of the subfornical organ during chronic changes in dietary salt.
Sodium balance, arterial pressure, and the role of the subfornical organ during chronic changes in dietary salt.
复制标题
钠平衡、动脉压和穹窿下器官在膳食盐慢性变化过程中的作用。
DOI：
10.1152/ajpheart.01051.2004
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Collister,JohnP
中科院分区：
文献类型：
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作者：
Hendel,MichaelD;Collister,JohnP
皮层下器官（SFO）是脑室周围器官之一，已知可介导与钠和水稳态相关的血管紧张素II的一些中枢作用。由于血管紧张素II水平随着长期饮食盐摄入量的变化而改变，我们推断血管紧张素II在SFO的作用可能参与了长期饮食盐摄入量变化过程中动脉压的调节。本研究旨在验证一种假设，即在饮食盐摄入量的慢性变化过程中，动脉压的长期控制需要完整的SFO。随机选取雄性Sprague-Dawley大鼠进行SFO电解损伤（SFOx,n= 8）或假手术（n= 9）。恢复期1周后，用无线遥测血压传感器连续24小时测量大鼠平均动脉压（MAP）和心率（HR），然后分别置于代谢笼中。恢复1周后，进行为期49天的试验：1)对照组（1.0% NaCl） 7 d,2)高盐（4.0% NaCl）饮食14 d，3)正常盐（1.0% NaCl）饮食7 d，4)低盐（0.1% NaCl）饮食14 d， 5)恢复期（1.0% NaCl饮食）7 d。在整个方案中，SFOx和假手术大鼠的MAP或HR没有显著差异。这些结果不支持SFO在膳食盐的慢性变化过程中对动脉压的调节是必要的假设。然而，在高盐饮食期的第2 - 6天，SFOx大鼠的累积钠平衡明显低于假手术大鼠。这些数据表明，在盐摄入量的慢性变化过程中，SFO对钠稳态的调节很重要。
The subfornical organ (SFO), one of the brain circumventricular organs, is known to mediate some of the central effects of angiotensin II related to sodium and water homeostasis. Because angiotensin II levels are altered with changes in chronic dietary salt intake, we reasoned that the actions of angiotensin II at the SFO might be involved in the regulation of arterial pressure during long-term alterations in dietary salt. The present study was designed to test the hypothesis that long-term control of arterial pressure during chronic changes in dietary salt intake requires an intact SFO. Male Sprague-Dawley rats were randomly selected for electrolytic lesion (SFOx,n= 8) or sham (n= 9) operation of the SFO. After a 1-wk recovery period, rats were instrumented with radio-telemetric blood pressure transducers for continuous 24-h measurement of mean arterial pressure (MAP) and heart rate (HR) and then were placed individually in metabolic cages. After another 1 wk of recovery, the rats were subjected to a 49-day protocol as follows:1) a 7-day control period (1.0% NaCl diet),2) 14 days of high-salt (4.0% NaCl) diet,3) 7 days of normal-salt (1.0% NaCl) diet,4) 14 days of low-salt (0.1% NaCl) diet, and5) 7 days of recovery (1.0% NaCl diet). There were no significant differences in MAP or HR between SFOx and sham-operated rats throughout the protocol. These results do not support the hypothesis that the SFO is necessary for regulation of arterial pressure during chronic changes in dietary salt. However, SFOx rats demonstrated significantly less cumulative sodium balance than sham-operated rats ondays 2–6of the high-salt diet period. These data suggest that the SFO is important in the regulation of sodium homeostasis during chronic changes in salt intake.