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Tubuloglomerular feedback signal transduction in a model of a compliant thick ascending limb
Author(s) -
Layton Harold E,
Moore Leon C,
Layton Anita T
Publication year - 2008
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.22.1_supplement.761.3
Subject(s) - tubuloglomerular feedback , harmonics , signal (programming language) , oscillation (cell signaling) , loop of henle , macula densa , chemistry , nephron , physics , computer science , voltage , medicine , biochemistry , renin–angiotensin system , quantum mechanics , renal function , blood pressure , programming language
We used a mathematical model to predict the impact of tubular compliance on tubuloglomerular feedback (TGF) signal transduction in the thick acending limb (TAL). In several previous studies, we used a mathematical model that represented the TAL as a rigid tube. That model predicts that TGF signal transduction by the TAL is a generator of nonlinearities: if a sinusoidal oscillation is added to constant intratubular fluid flow, the NaCl concentration alongside the macula densa will be nonsinusoidal owing to an accumulation of harmonics. We have hypothesized that complexity found in power spectra based on in vivo time series of key TGF variables arises in part from those harmonics and that nonlinearities in TGF‐mediated oscillations may result in increased NaCl delivery to the distal nephron. To address the concern that a more realistic TAL would damp harmonics, we have conducted simulations in a model TAL that has compliant walls and thus a tubular radius that depends on transmural pressure. These simulations predict that compliant TAL walls do not damp, but instead, intensify the harmonics. This research supported in part by NSF grant DMS‐0715021 and NIH grant DK‐42091.