Math @ Duke

Publications [#287287] of Harold Layton
Papers Published
 Layton, HE, Distributed loops of Henle in a central core model of the renal medulla: Where should the solute come out?,
Mathematical and Computer Modelling, vol. 14 no. C
(1990),
pp. 533537, Elsevier BV, ISSN 08957177 [doi]
(last updated on 2019/01/24)
Abstract: In the mammalian kidney the number of loops of Henle decreases as a function of medullary depth. The role of this decreasing loop population was studied in a steadystate, central core model of the renal inner medulla under simple assumptions: there is no axial diffusion in the central core; the osmolalities in the central core, the descending limbs, and the collecting ducts are equal at each medullary level; and the concentration gradient is generated through the reabsorption of solute from the waterimpermeable ascending limbs. A continuous approximation to the loop distribution in rats was based on experimental data. When solute is transported from the ascending limbs with a spatially uniform transport rate, similar in magnitude to the transport rate from the thick ascending limbs of the outer medulla, a moderate gradient is generated in the inner medulla. A steeper gradient, however, is generated by a transport rate that is largest near the turns in the loops, but which is scaled so that the total solute transport is unchanged. When loop distributions that decrease more slowly than those found in rats are used in the model, concentrating capability is decreased for both transportrate assumptions. These results indicate that the conclusions reached in an earlier study under less accurate physiological assumptions also hold in a central core model. © 1990.


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