Comparison of central core and radially separated models of renal inner medulla.
Comparison of central core and radially separated models of renal inner medulla.
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肾内髓质中央核心模型和径向分离模型的比较。
DOI：
10.1152/ajprenal.1995.268.4.f693
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Stephenson,JL
中科院分区：
文献类型：
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作者：
Jen,JF;Wang,H;Tewarson,RP;Stephenson,JL
本文描述了在肾内髓浓缩机制的数学模型中，中央血管间隙（CORE）和径向分离的毛细血管结（NODE）之间的升支细肢（ATL）和集合管（CD）的分配交换的作用。该模型的详细描述已提供[J. L.斯蒂芬森。珍，H. Wang和R. P. Tewarson。Am. J.Physiol.268（Renal Fluid Electrolyte Physiol.37）：F680-F692，1995]。我们定义了一个分配系数θ，它表示CD和ATL与NODE的分数交换。因此，当θ = 0时，我们有一个中心核模型，其中ATL和CD只与CORE交换，当θ = 1时，我们有一个完全径向分离的模型，其中ATL和CD只与NODE交换。将分配系数从1减小到0实现了从完全径向分离的模型到中心核模型的连续过渡。随着这种转变的进展，与CORE的交换增加，所有结构中的渗透压在乳头处变得几乎相同，并且失去了向上运输盐的能力。即使没有径向扩散也是如此。然而，径向扩散和直接交换与核心协同作用，在降低渗透压差的乳头和对流上坡运输的能力。它们或多或少以平行的方式消失。然而，注意力集中能力没有显著的伴随变化。这些结果表明，模型与径向混合的间质血管空间可能是合理的好近似的内部髓质。
In this paper we describe the effect of partitioning exchange of ascending thin limb (ATL) and collecting duct (CD) between a central vascular space (CORE) and a radially separated capillary node (NODE) in a mathematical model of the concentrating mechanism of the renal inner medulla. A detailed description of the model has been provided [J. L. Stephenson, J. F. Jen, H. Wang, and R. P. Tewarson. Am. J. Physiol. 268 (Renal Fluid Electrolyte Physiol. 37): F680–F692, 1995]. We define a partition coefficient theta, which denotes the fractional exchange of CD and ATL with the NODE. Thus with theta = 0 we have a central core model, in which the ATL and CD exchange with the CORE only, and with theta = 1 we have a totally radially separated model, in which the ATL and CD exchange with the NODE only. Decreasing the partition coefficient from 1 to 0 effects a continuous transition from a totally radially separated model to a central core model. As this transition progresses with increasing exchange with the CORE, the osmolalities in all structures become nearly the same at the papilla, and the ability to transport salt uphill is lost. This is true even with no radial diffusion. However, radial diffusion and direct exchange with the CORE act synergistically in decreasing osmolality differences at the papilla and the capacity for convective uphill transport. These are lost in a more or less parallel way. There is, however, no significant concomitant change in concentrating ability. These results indicate that models with radial mixing of the interstitial vascular space are probably reasonably good approximations for the inner medulla.