| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Biology & Centre for Biomedical Research, University of Victoria, Victoria, Canada
2 Medicine & Physiology, University of Alberta, Edmonton, Canada
* To whom correspondence should be addressed. E-mail: wcupples{at}uvic.ca.
The kidney displays highly efficient autoregulation so that under steady state conditions renal blood flow (RBF) is independent of blood pressure over a wide range of pressure. Autoregulation occurs in the pre-glomerular microcirculation and is mediated by two, perhaps three, mechanisms. The faster myogenic mechanism and the slower tubuloglomerular feedback contribute both directly and interactively to autoregulation of RBF and of glomerular capillary pressure. Multiple experiments have been used to study autoregulation and can be considered as variants of two basic designs. The first measures RBF after multiple stepwise changes of renal perfusion pressure to assess how a biological condition or experimental maneuver affects the overall pressure-flow relationship. The second uses time-series analysis to better understand the operation of multiple controllers operating in parallel on the same vascular smooth muscle. There are conceptual and experimental limitations to all current experimental designs so that no one design adequately describes autoregulation. In particular it is clear that the efficiency of autoregulation varies with time and that most current techniques do not adequately address this issue. Also, the time-varying and non-additive interaction between the myogenic mechanism and tubuloglomerular feedback underscores the difficulty of dissecting their contributions to autoregulation. We consider the modulation of autoregulation by nitric oxide and use it to illustrate the necessity for multiple experimental designs, often applied iteratively.
This article has been cited by other articles:
|
|
 |
|
  K. H. Chon, Y. Zhong, L. C. Moore, N. H. Holstein-Rathlou, and W. A. Cupples Analysis of nonstationarity in renal autoregulation mechanisms using time-varying transfer and coherence functions Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2008; 295(3): R821 - R828. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Iliescu, R. Cazan, G. R. McLemore Jr., M. Venegas-Pont, and M. J. Ryan Renal blood flow and dynamic autoregulation in conscious mice Am J Physiol Renal Physiol, September 1, 2008; 295(3): F734 - F740. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Kleinstreuer, T. David, M. J. Plank, and Z. Endre Dynamic myogenic autoregulation in the rat kidney: a whole-organ model Am J Physiol Renal Physiol, June 1, 2008; 294(6): F1453 - F1464. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. A. Griffin, M. Abu-Naser, I. Abu-Amarah, M. Picken, G. A. Williamson, and A. K. Bidani Dynamic blood pressure load and nephropathy in the ZSF1 (fa/facp) model of type 2 diabetes Am J Physiol Renal Physiol, November 1, 2007; 293(5): F1605 - F1613. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. S. Michel, R. Y. K. Man, and P. M. Vanhoutte Increased spontaneous tone in renal arteries of spontaneously hypertensive rats Am J Physiol Heart Circ Physiol, September 1, 2007; 293(3): H1673 - H1681. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
