Premium
Tubular Fluid Oscillations Mediated by Tubuloglomerular Feedback in a Short Loop of Henle
Author(s) -
Ryu Hwayeon,
Layton Anita T.
Publication year - 2012
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.26.1_supplement.690.1
Subject(s) - tubuloglomerular feedback , loop of henle , chemistry , mechanics , loop (graph theory) , physics , regulator , radius , bifurcation , control theory (sociology) , thermodynamics , mathematics , nonlinear system , sodium , renal function , computer science , biochemistry , reabsorption , computer security , organic chemistry , control (management) , combinatorics , quantum mechanics , artificial intelligence , gene
The tubuloglomerular feedback (TGF) system in the rat kidney, which is a key regulator of filtration rate, has been shown in physiologic experiments to mediate oscillations in tubular fluid pressure and flow, and in NaCl concentration in tubular fluid of the loop of Henle. We developed a mathematical model of the TGF system that represents NaCl transport along a short loop of Henle with compliant walls. A bifurcation analysis of the TGF model equations was performed by deriving and finding roots of the characteristic equation arising from a linearization of the model equations. The analysis revealed a complex parameter region that allows a variety of qualitatively different model equations, including stable time‐independent steady‐state solution and oscillatory solution. Model results suggest that a higher thick ascending limb (TAL) NaCl active transport rate or a smaller TAL radius near the loop‐bend gives rise to stable oscillatory solutions at sufficiently high TGF gain values, even with zero TGF delay. Also, tubular wall compliance increases the tendency of the TGF system to oscillate. This research was supported in part by NIH grant DK‐89066 and by NSF grant DMS‐0715021.