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Mathematical model of ammonia handling in the rat renal medulla (891.3)
Author(s) -
Noiret Lorette,
Thomas S. Randall
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.891.3
Subject(s) - ammonia , nephron , urea , renal medulla , excretion , chemistry , kidney , potassium , urine , endocrinology , medicine , biochemistry , organic chemistry
Ammonia produced in the kidney can be absorbed into the renal vein or excreted in urine. We developed a mathematical model of the rat renal medulla in order to identify some of the components controlling the fate of renal ammonia. The model simulates the movements of water, sodium, urea, NH3, NH4+ and a non‐reabsorbable solute along nephrons and vasa recta of various lengths and includes pH, potassium concentrations, and electrical potential as imposed boundary conditions at each medullary depth. A sensitivity analysis was performed to identify the transport parameters and micro‐environmental conditions that have the greatest effect on the simulated rate of urinary ammonia excretion. Our results suggest that urinary ammonia excretion is mainly controlled by the parameters that affect ammonia delivery to the descending segment of short nephron. In particular, interstitial pH in the outer medulla seems to be critical. The model provides the first coordinated picture of renal ammonia handling. Grant Funding Source : Supported by the EPSRC through the UCL CoMPLEX doctoral training centre (UK).