| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Medicine, Division of Nephrology, University of Maryland, Baltimore, MD, USA
2 Department of Medicine, Division of Nephrology, University of Maryland, Baltimore, MD, USA; Department of Physiology, University of Maryland, Baltimore, MD, USA
* To whom correspondence should be addressed. E-mail: tpallone{at}medicine.umaryland.edu.
Response of Descending Vasa Recta to Luminal Pressure. We tested whether luminal perfusion and pressurization induces an endothelial cytoplasmic Ca2+ ([Ca2+]CYT) response in descending vasa recta (DVR). DVR isolated from the rat outer medulla were cannulated and subjected to free flow microperfusion (5 nl/min), onset of which increased [Ca2+]CYT from a baseline of 76 ± 13 to 221 ± 65 nM. Graded increase in luminal pressure from 0 to 45 mmHg in stopped flow experiments induced a parallel increase in [Ca2+]CYT from a baseline of 74 ± 24 to 194 ± 33 nM at 45 mmHg, with tendency for [Ca2+]CYT to plateau at pressures > 25 mmHg. Removal of extracellular Ca2+ and blockade by either La3+ (10 µM) or SKF96365 (100 µM) eliminated the response. Luminal pressurization to 25 mmHg increased NO generation, a response blocked by NO synthase inhibition or removal of extracellular Ca2+. The NO generation was not affected by the superoxide dismutase mimetic, tempol. We conclude that DVR endothelia are mechanosensitive and respond to luminal pressure by elevating [Ca2+]CYT and generating NO. That response might augment medullary perfusion and saliuresis.
This article has been cited by other articles:
|
|
 |
|
  M. Sendeski, A. Patzak, T. L. Pallone, C. Cao, A. E. Persson, and P. B. Persson Iodixanol, Constriction of Medullary Descending Vasa Recta, and Risk for Contrast Medium-induced Nephropathy Radiology, June 1, 2009; 251(3): 697 - 704. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. Lee-Kwon, J. H. Goo, Z. Zhang, E. P. Silldorff, and T. L. Pallone Vasa recta voltage-gated Na+ channel Nav1.3 is regulated by calmodulin Am J Physiol Renal Physiol, January 1, 2007; 292(1): F404 - F414. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Q. Zhang, C. Cao, M. Mangano, Z. Zhang, E. P. Silldorff, W. Lee-Kwon, K. Payne, and T. L. Pallone Descending vasa recta endothelium is an electrical syncytium Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2006; 291(6): R1688 - R1699. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Pittner, K. Rhinehart, and T. L. Pallone Ouabain modulation of endothelial calcium signaling in descending vasa recta Am J Physiol Renal Physiol, October 1, 2006; 291(4): F761 - F769. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M.-h. Kim, N. R. Harris, and J. M. Tarbell Regulation of hydraulic conductivity in response to sustained changes in pressure Am J Physiol Heart Circ Physiol, December 1, 2005; 289(6): H2551 - H2558. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Herrera and J. L. Garvin Recent Advances in the Regulation of Nitric Oxide in the Kidney Hypertension, June 1, 2005; 45(6): 1062 - 1067. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. Lee-Kwon, J. B. Wade, Z. Zhang, T. L. Pallone, and E. J. Weinman Expression of TRPC4 channel protein that interacts with NHERF-2 in rat descending vasa recta Am J Physiol Cell Physiol, April 1, 2005; 288(4): C942 - C949. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
