Tubular fluid flow and distal NaCl delivery mediated by tubuloglomerular feedback in the rat kidney.
Tubular fluid flow and distal NaCl delivery mediated by tubuloglomerular feedback in the rat kidney.
复制标题
大鼠肾脏中肾小管肾小球反馈介导的肾小管液流和远端 NaCl 输送。
DOI：
10.1007/s00285-013-0667-5
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发表时间：
2014
影响因子：
1.9
通讯作者：
Layton,AnitaT
中科院分区：
文献类型：
--
作者：
Ryu,Hwayeon;Layton,AnitaT
肾脏中的肾小球滤过率部分地由肾小管肾小球反馈（TGF）系统控制，该系统是介导Henle环的肾小管流体流动和流体NaCl浓度的振荡的负反馈环。在这项研究中，我们开发了一个数学模型的转化生长因子系统，表示NaCl运输沿着一个短的亨利环与顺应性的墙壁。近端小管和下行肢的外条纹段被认为是高透水性的;厚的上行肢（TAL）被认为是不透水的，并具有积极的NaCl运输。通过计算参数边界，TGF增益和延迟的函数，分离不同的模型行为的TGF模型方程的分叉分析。分析揭示了一个复杂的参数区域，允许各种定性不同的模型方程：一个政权有一个稳定的，与时间无关的稳态解和政权具有不同频率的稳定振荡的解决方案。与以前的模型，它只代表TAL明确和其他部分使用现象学关系的比较表明，显式表示的近端小管和下降肢的循环的亨利降低了TGF系统的稳定性。模型模拟还表明，极限环振荡的开始导致时间平均远端NaCl输送的增加，而远端液体输送没有太大影响。
The glomerular filtration rate in the kidney is controlled, in part, by the tubuloglomerular feedback (TGF) system, which is a negative feedback loop that mediates oscillations in tubular fluid flow and in fluid NaCl concentration of the loop of Henle. In this study, we developed a mathematical model of the TGF system that represents NaCl transport along a short loop of Henle with compliant walls. The proximal tubule and the outer-stripe segment of the descending limb are assumed to be highly water permeable; the thick ascending limb (TAL) is assumed to be water impermeable and have active NaCl transport. A bifurcation analysis of the TGF model equations was performed by computing parameter boundaries, as functions of TGF gain and delay, that separate differing model behaviors. The analysis revealed a complex parameter region that allows a variety of qualitatively different model equations: a regime having one stable, time-independent steady-state solution and regimes having stable oscillatory solutions of different frequencies. A comparison with a previous model, which represents only the TAL explicitly and other segments using phenomenological relations, indicates that explicit representation of the proximal tubule and descending limb of the loop of Henle lowers the stability of the TGF system. Model simulations also suggest that the onset of limit-cycle oscillations results in increases in the time-averaged distal NaCl delivery, whereas distal fluid delivery is not much affected.