An online tool for calculation of free-energy balance for the renal inner medulla

作者：Vilbig Ryan L; Sarkar Abhijit; Zischkau Joseph; Knepper Mark A^*; Pisitkun Trairak

来源：American Journal of Physiology - Renal Fluid and Electrolyte Physiology, 2012, 303(3): F366-F372.

DOI：10.1152/ajprenal.00147.2012

• kidney
• mathematical model
• urine concentrating mechanism

Vilbig RL, Sarkar A, Zischkau J, Knepper MA, Pisitkun T. An online tool for calculation of free-energy balance for the renal inner medulla. Am J Physiol Renal Physiol 303: F366-F372, 2012. First published May 30, 2012; doi:10.1152/ajprenal.00147.2012.-Concentrating models of the renal inner medulla can be classified according to external free-energy balance into passive models (positive values) and models that require an external energy source (negative values). Here we introduce an online computational tool that implements the equations of Stephenson and colleagues (Stephenson JL, Tewarson RP, Mejia R. Proc Natl Acad Sci USA 71: 1618-1622, 1974) to calculate external free-energy balance at steady state for the inner medulla (http://helixweb.nih.gov/ESBL/FreeEnergy). Here %26quot;external free-energy balance%26quot; means the sum of free-energy flows in all streams entering and leaving the inner medulla. The program first assures steady-state mass balance for all components and then tallies net external free-energy balance for the selected flow conditions. Its use is illustrated by calculating external free-energy balance for an example of the passive concentrating model taken from the original paper by Kokko and Rector (Kokko JP, Rector FC Jr. Kidney Int 2: 214-223, 1972).

• 出版日期2012-8