Departamento de Fisiologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brasil.
Braz J Med Biol Res. 2011 Sep;44(9):877-82. doi: 10.1590/s0100-879x2011007500092. Epub 2011 Jul 22.
Water deprivation and hypernatremia are major challenges for water and sodium homeostasis. Cellular integrity requires maintenance of water and sodium concentration within narrow limits. This regulation is obtained through engagement of multiple mechanisms and neural pathways that regulate the volume and composition of the extracellular fluid. The purpose of this short review is to summarize the literature on central neural mechanisms underlying cardiovascular, hormonal and autonomic responses to circulating volume changes, and some of the findings obtained in the last 12 years by our laboratory. We review data on neural pathways that start with afferents in the carotid body that project to medullary relays in the nucleus tractus solitarii and caudal ventrolateral medulla, which in turn project to the median preoptic nucleus in the forebrain. We also review data suggesting that noradrenergic A1 cells in the caudal ventrolateral medulla represent an essential link in neural pathways controlling extracellular fluid volume and renal sodium excretion. Finally, recent data from our laboratory suggest that these structures may also be involved in the beneficial effects of intravenous infusion of hypertonic saline on recovery from hemorrhagic shock.
缺水和高钠血症是水和钠动态平衡的主要挑战。细胞完整性要求在狭窄的范围内维持水和钠浓度。这种调节是通过参与多种机制和神经途径来实现的，这些机制和神经途径调节细胞外液的体积和组成。本文的目的是总结有关中枢神经机制的文献，这些机制是心血管、激素和自主反应对循环血量变化的基础，也是我们实验室在过去 12 年中获得的部分发现。我们回顾了有关神经通路的资料，这些神经通路始于颈动脉体的传入神经，投射到孤束核和尾侧腹外侧髓质中的中继，而后者又投射到前脑的中脑视前核。我们还回顾了一些数据，这些数据表明，尾侧腹外侧髓质中的去甲肾上腺素能 A1 细胞代表了控制细胞外液体积和肾脏钠排泄的神经通路中的一个重要环节。最后，我们实验室的最新数据表明，这些结构可能也参与了静脉输注高渗盐水对失血性休克恢复的有益作用。
