| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
* To whom correspondence should be addressed. E-mail: tpallone{at}medicine.umaryland.edu.
We tested whether chronic angiotensin II infusion into rats affects descending vasa recta (DVR) contractility, synthesis of superoxide or synthesis of nitric oxide (NO). Rats were infused with AngII at 250 ng Kg-1 min-1 for 11 to 13 days. DVR were loaded with dihydroethidium (DHE) to measure superoxide and 3-amino, 4-aminomethyl-2',7'-difluorofluorescein (DAFFM) to measure NO. Acute constriction of DVR by AngII (0.1, 1, 10 nM) was diminished and NO generation rate was raised by chronic AngII infusion. DHE oxidation by DVR from AngII infused rats was similar to controls and was significantly higher when NO synthesis was prevented with n
-nitro-L-arginine methyl ester (LNAME). The superoxide dismutase mimetic, tempol (1 mM) increased NO generation compared to controls. The increased synthesis of NO by chronic AngII treated vessels persisted in the presence of tempol. DVR endothelial cytoplasmic Ca2+ response to acetylcholine (ACh) was diminished by chronic AngII treatment but the capacity of ACh to increase NO generation was unaltered. We conclude that DVR generation of superoxide is not affected by chronic AngII exposure but that basal NO synthesis is increased. DVR superoxide superoxide is unlikely to be an important mediator of chronic AngII slow pressor hypertension in rats.
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]
|
|
|
|
 |
|
 C. Cao, K. Payne, W. Lee-Kwon, Z. Zhang, S. W. Lim, J. Hamlyn, M. P. Blaustein, H. M. Kwon, and T. L. Pallone Chronic ouabain treatment induces vasa recta endothelial dysfunction in the rat Am J Physiol Renal Physiol, January 1, 2009; 296(1): F98 - F106. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. S. Wilcox and A. Pearlman Chemistry and Antihypertensive Effects of Tempol and Other Nitroxides Pharmacol. Rev., December 1, 2008; 60(4): 418 - 469. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Chen, K. Patel, S. G. Connors, M. Mendonca, W. J. Welch, and C. S. Wilcox Acute antihypertensive action of Tempol in the spontaneously hypertensive rat Am J Physiol Heart Circ Physiol, December 1, 2007; 293(6): H3246 - H3253. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Zhang and A. Edwards A model of nitric oxide tubulovascular cross talk in a renal outer medullary cross section Am J Physiol Renal Physiol, February 1, 2007; 292(2): F711 - F722. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Abe, P. O'Connor, M. Kaldunski, M. Liang, R. J. Roman, and A. W. Cowley Jr. Effect of sodium delivery on superoxide and nitric oxide in the medullary thick ascending limb Am J Physiol Renal Physiol, August 1, 2006; 291(2): F350 - F357. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. S. Wilcox Oxidative stress and nitric oxide deficiency in the kidney: a critical link to hypertension? Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2005; 289(4): R913 - R935. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. S. Wilcox and D. Gutterman Focus on oxidative stress in the cardiovascular and renal systems Am J Physiol Heart Circ Physiol, January 1, 2005; 288(1): H3 - H6. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
