Bifurcation analysis of nephron pressure and flow regulation.
One- and two-dimensional continuation techniques are applied to study the bifurcation structure of a model of renal flow and pressure control. Integrating the main physiological mechanisms by which the individual nephron regulates the incoming blood flow, the model describes the interaction between the tubuloglomerular feedback and the response of the afferent arteriole. It is shown how a Hopf bifurcation leads the system to perform self-sustained oscillations if the feedback gain becomes sufficiently strong, and how a further increase of this parameter produces a folded structure of overlapping period-doubling cascades. Similar phenomena arise in response to increasing blood pressure. The numerical analyses are supported by existing experimental results on anesthetized rats. (c) 1996 American Institute of Physics.
Barfred
Mikael
M
Center for Chaos and Turbulence Studies, Department of Physics, The Technical University of Denmark, 2800 Lyngby, DenmarkDepartment of Medical Physiology, Panum Institute, The University of Copenhagen, 2200 Copenhagen N, Denmark.
Mosekilde
Erik
E
Holstein-Rathlou
Niels-Henrik
NH