| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Physiology and Biophysics, University of South Florida, Tampa, FL, USA
* To whom correspondence should be addressed. E-mail: dyip{at}hsc.usf.edu.
The effect of acute arterial hypertension on proximal tubular fluid reabsorption was investigated in Sprague-Dawley rats and spontaneously hypertensive rats (SHR) by measuring proximal tubular flow with a non-obstructive optical method. Under control conditions, spontaneous tubular flow was oscillating at 0.02-0.03 Hz in Sprague-Dawley rats. Acute hypertension induced an immediate increase of mean tubular flow (50% increase after 20 min of hypertension) and augmentation of oscillatory amplitude. Acute hypertension did not alter single nephron blood flow as measured by laser Doppler velocimetry (n= 12), suggesting that the increase of tubular flow was due to inhibition of reabsorption but not increase of filtration. By contrast, spontaneous tubular flow was fluctuating aperiodically in SHR. Acute hypertension did not induce a continuous increase of tubular flow nor an increase in amplitude of fluctuations (n=15). When apical Na+/H+ exchanger activity of proximal tubule was monitored, acute hypertension did not alter the activity in SHR (n=8), while similar procedure had been shown to inhibit apical Na+/H+ exchanger activity of proximal tubules by more than 40% in Sprague-Dawley rats. These observations suggest that acute hypertension inhibits proximal tubular fluid reabsorption by inhibiting apical Na+/H+ exchanger activity in Sprague-Dawley rats, and that this mechanism is impaired in SHR.
This article has been cited by other articles:
|
|
 |
|
  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]
|
|
|
|
 |
|
 A. T. Layton, L. C. Moore, and H. E. Layton Multistability in tubuloglomerular feedback and spectral complexity in spontaneously hypertensive rats Am J Physiol Renal Physiol, July 1, 2006; 291(1): F79 - F97. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. K. K. Leong, L. E. Yang, C. S. Landon, A. A. McDonough, and K.-P. Yip Phenol injury-induced hypertension stimulates proximal tubule Na+/H+ exchanger activity Am J Physiol Renal Physiol, June 1, 2006; 290(6): F1543 - F1550. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. K. K. Leong, A. Devillez, M. B. Sandberg, L. E. Yang, D. K. P. Yip, J. B. Klein, and A. A. McDonough Effects of ACE inhibition on proximal tubule sodium transport Am J Physiol Renal Physiol, April 1, 2006; 290(4): F854 - F863. [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]
|
|
|
|
|
|
K.-P. Yip Flash photolysis of caged nitric oxide inhibits proximal tubular fluid reabsorption in free-flow nephron Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2005; 289(2): R620 - R626. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
