| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Internal Medicine, Loyola University Medical Center, Maywood, IL, USA; Department of Internal Medicine, Edward Hines Jr. VA Hospital, Hines, IL, USA
2 Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, IL, USA
3 Department of Internal Medicine, Loyola University Medical Center, Maywood, IL, USA
4 Department of Pharmacology & Therapeutics, University of Calgary, Alberta, Calgary, Canada
5 Department of Internal Medicine, Edward Hines Jr. VA Hospital, Hines, IL, USA; Department of Internal Medicine, Loyola University Medical Center, Maywood, IL, USA
* To whom correspondence should be addressed. E-mail: abidani{at}lumc.edu.
Renal autoregulatory (AR) mechanisms provide the primary protection against transmission of systemic pressures and their impairment is believed to be responsible for the enhanced susceptibility to hypertensive renal damage in renal mass reduction (RMR) models. Assessment of AR capacity by the 'step'change methodology under anesthesia was compared to that by 'dynamic' methods in separate conscious control Sprague-Dawley rats and after uninephrectomy (UNX) and 3/4 RMR (RK-NX) (n=7-10/group). Substantially less AR capacity was seen by the 'dynamic' vs. the 'step' methodology in control rats. Moreover, 'dynamic' AR capacity did not differ between controls, UNX and RK-NX rats (fractional gain in admittance ~0.4 to 0.5 in all groups at frequencies in the range of 0.0025 to 0.025 Hz). By contrast, significant impairment of step AR was seen in RK-NX vs. control or UNX rats (autoregulatory indices 0.7±0.1 vs. 0.1±0.02 and 0.2±0.04 respectively, p<0.01). We propose that the 'step' and 'dynamic' methods evaluate the renal AR responses to different components of BP power with the 'step' AR assessing the ability to buffer large changes in average BP (DC Power) while the current methods assess the AR ability to buffer slow BP fluctuations (<0.25Hz) superimposed on the average BP (AC power), a substantially smaller component of total BP power. We further suggest that 'step' but not 'dynamic' AR methods as currently performed provide a valid index of the underlying susceptibility to hypertensive glomerular damage after RMR.
This article has been cited by other articles:
|
|
 |
|
  E. Seeliger, T. Wronski, M. Ladwig, L. Dobrowolski, T. Vogel, M. Godes, P. B. Persson, and B. Flemming The renin-angiotensin system and the third mechanism of renal blood flow autoregulation Am J Physiol Renal Physiol, June 1, 2009; 296(6): F1334 - F1345. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. D. Bell, G. F. DiBona, R. Biemiller, and M. W. Brands Continuously measured renal blood flow does not increase in diabetes if nitric oxide synthesis is blocked Am J Physiol Renal Physiol, November 1, 2008; 295(5): F1449 - F1456. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 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]
|
|
|
|
 |
|
 M. W. Brands and H. Labazi Role of Glomerular Filtration Rate in Controlling Blood Pressure Early in Diabetes Hypertension, August 1, 2008; 52(2): 188 - 194. [Full Text] [PDF]
|
|
|
|
|
|
K. A. Griffin, H. Kramer, and A. K. Bidani Adverse renal consequences of obesity Am J Physiol Renal Physiol, April 1, 2008; 294(4): F685 - F696. [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]
|
|
|
|
|
|
W. A. Cupples and B. Braam Assessment of renal autoregulation Am J Physiol Renal Physiol, April 1, 2007; 292(4): F1105 - F1123. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. K. Bidani, M. Picken, R. Hacioglu, G. Williamson, and K. A. Griffin Spontaneously reduced blood pressure load in the rat streptozotocin-induced diabetes model: potential pathogenetic relevance Am J Physiol Renal Physiol, February 1, 2007; 292(2): F647 - F654. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Just Mechanisms of renal blood flow autoregulation: dynamics and contributions Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2007; 292(1): R1 - R17. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Loutzenhiser, K. Griffin, G. Williamson, and A. Bidani Renal autoregulation: new perspectives regarding the protective and regulatory roles of the underlying mechanisms Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2006; 290(5): R1153 - R1167. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Hashimoto, Y. Huang, J. Briggs, and J. Schnermann Reduced autoregulatory effectiveness in adenosine 1 receptor-deficient mice Am J Physiol Renal Physiol, April 1, 2006; 290(4): F888 - F891. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Just and W. J. Arendshorst Nitric oxide blunts myogenic autoregulation in rat renal but not skeletal muscle circulation via tubuloglomerular feedback J. Physiol., December 15, 2005; 569(3): 959 - 974. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Abu-Amarah, A. K. Bidani, R. Hacioglu, G. A. Williamson, and K. A. Griffin Differential effects of salt on renal hemodynamics and potential pressure transmission in stroke-prone and stroke-resistant spontaneously hypertensive rats Am J Physiol Renal Physiol, August 1, 2005; 289(2): F305 - F313. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. W. Kurtz, K. A. Griffin, A. K. Bidani, R. L. Davisson, and J. E. Hall Recommendations for Blood Pressure Measurement in Humans and Experimental Animals: Part 2: Blood Pressure Measurement in Experimental Animals. A Statement for Professionals From the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research Arterioscler Thromb Vasc Biol, March 1, 2005; 25(3): e22 - e33. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. W. Kurtz, K. A. Griffin, A. K. Bidani, R. L. Davisson, and J. E. Hall Recommendations for Blood Pressure Measurement in Humans and Experimental Animals: Part 2: Blood Pressure Measurement in Experimental Animals: A Statement for Professionals From the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research Hypertension, February 1, 2005; 45(2): 299 - 310. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. A. Griffin, R. Hacioglu, I. Abu-Amarah, R. Loutzenhiser, G. A. Williamson, and A. K. Bidani Effects of calcium channel blockers on "dynamic" and "steady-state step" renal autoregulation Am J Physiol Renal Physiol, June 1, 2004; 286(6): F1136 - F1143. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
