| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Division of Nephrology and Lady Davis Institute, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec H3T 1E2; and 2 Smooth Muscle Research Group and Department of Pharmacology and Therapeutics, University of Calgary, Calgary, Alberta, Canada T2N 4N1
Renal autoregulation is mediated by
tubuloglomerular feedback, operating at 0.03-0.05 Hz, and a faster
system, operating at 0.1-0.2 Hz, that has been attributed by
exclusion to myogenic vasoconstriction. In this study, we examined
dynamic autoregulation in the hydronephrotic rat kidney, which lacks
tubuloglomerular feedback but exhibits pressure-induced afferent
arteriolar vasoconstriction. Kidneys were harvested under anesthesia
from Sprague-Dawley rats and perfused in vitro using defined,
colloid-free medium. Renal perfusate flow was assessed during forced
pressure fluctuations at mean pressures of 60-140 mmHg. Transfer
function analysis revealed passive behavior at 60 mmHg and active,
pressure-dependent responses at higher pressures. In all cases,
coherence was high (0.89 ± 0.03 between 0.01 and 0.9 Hz). There was
a resonance peak in admittance gain at 
0.3 Hz and an associated
broad peak in phase angle. Below this frequency, gain declined
progressively. The minimum gain achieved at 0.01-0.05 Hz was
pressure sensitive, being 1.08 ± 0.02 at 60 mmHg and 0.71 ± 0.04 at 140 mmHg. These findings are consistent with in vivo results
and with model-based predictions of the dynamics of myogenic
autoregulation, supporting the postulate that the rapid component of
autoregulation reflects operation of a myogenic mechanism.
renal autoregulation; myogenic; transfer function; pressure; flow
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]
|
|
|
|
 |
|
 X. Wang, K. Takeya, P. I. Aaronson, K. Loutzenhiser, and R. Loutzenhiser Effects of amiloride, benzamil, and alterations in extracellular Na+ on the rat afferent arteriole and its myogenic response Am J Physiol Renal Physiol, July 1, 2008; 295(1): F272 - F282. [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]
|
|
|
|
|
|
X. Wang, R. D. Loutzenhiser, and W. A. Cupples Frequency modulation of renal myogenic autoregulation by perfusion pressure Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2007; 293(3): R1199 - R1204. [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]
|
|
|
|
|
|
X. Wang, J. Breaks, K. Loutzenhiser, and R. Loutzenhiser Effects of inhibition of the Na+/K+/2Cl- cotransporter on myogenic and angiotensin II responses of the rat afferent arteriole Am J Physiol Renal Physiol, March 1, 2007; 292(3): F999 - F1006. [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]
|
|
|
|
 |
|
 T. D. Bell, G. F. DiBona, Y. Wang, and M. W. Brands Mechanisms for Renal Blood Flow Control Early in Diabetes as Revealed by Chronic Flow Measurement and Transfer Function Analysis J. Am. Soc. Nephrol., August 1, 2006; 17(8): 2184 - 2192. [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]
|
|
|
|
|
|
Y. Shi, X. Wang, K. H. Chon, and W. A. Cupples Tubuloglomerular feedback-dependent modulation of renal myogenic autoregulation by nitric oxide Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2006; 290(4): R982 - R991. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Marsh, O. V. Sosnovtseva, K. H. Chon, and N.-H. Holstein-Rathlou Nonlinear interactions in renal blood flow regulation Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2005; 288(5): R1143 - R1159. [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]
|
|
|
|
|
|
C. Julien, B. Chapuis, Y. Cheng, and C. Barres Dynamic interactions between arterial pressure and sympathetic nerve activity: role of arterial baroreceptors Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2003; 285(4): R834 - R841. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Wronski, E. Seeliger, P. B. Persson, C. Forner, C. Fichtner, J. Scheller, and B. Flemming The step response: a method to characterize mechanisms of renal blood flow autoregulation Am J Physiol Renal Physiol, October 1, 2003; 285(4): F758 - F764. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. K. Bidani, R. Hacioglu, I. Abu-Amarah, G. A. Williamson, R. Loutzenhiser, and K. A. Griffin "Step" vs. "dynamic" autoregulation: implications for susceptibility to hypertensive injury Am J Physiol Renal Physiol, July 1, 2003; 285(1): F113 - F120. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. M. Smith, L. C. Moore, and H. E. Layton Advective transport of nitric oxide in a mathematical model of the afferent arteriole Am J Physiol Renal Physiol, May 1, 2003; 284(5): F1080 - F1096. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Chilton and R. Loutzenhiser Functional Evidence for an Inward Rectifier Potassium Current in Rat Renal Afferent Arterioles Circ. Res., February 2, 2001; 88(2): 152 - 158. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Walker III, L. M. Harrison-Bernard, A. K. Cook, and L. G. Navar Dynamic interaction between myogenic and TGF mechanisms in afferent arteriolar blood flow autoregulation Am J Physiol Renal Physiol, November 1, 2000; 279(5): F858 - F865. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. C. Malpas, T. A. Hore, M. Navakatikyan, E. V. Lukoshkova, S. K. Nguang, and P. C. Austin Resonance in the renal vasculature evoked by activation of the sympathetic nerves Am J Physiol Regulatory Integrative Comp Physiol, May 1, 1999; 276(5): R1311 - R1319. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Abu-Amarah, D. O. Ajikobi, H. Bachelard, W. A. Cupples, and F. C. Salevsky Responses of mesenteric and renal blood flow dynamics to acute denervation in anesthetized rats Am J Physiol Regulatory Integrative Comp Physiol, November 1, 1998; 275(5): R1543 - R1552. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. A. Kirton and R. Loutzenhiser Alterations in basal protein kinase C activity modulate renal afferent arteriolar myogenic reactivity Am J Physiol Heart Circ Physiol, August 1, 1998; 275(2): H467 - H475. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
