|
|
||||||||
1 Department of Physiology and Biophysics, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096; and 2 Department of Vascular Surgery, Rambam Medical Center, Haifa 31096, Israel
The generation of
PGs from arachidonic acid is mediated by cyclooxygenase (COX),
which consists of a constitutive (COX-1) and an inducible (COX-2)
isoform. The present study evaluated the relative expression and
immunoreactive levels of COX-1 and COX-2, by means of RT-PCR, Western
blot analysis, and immunohistochemistry, in the renal cortex and
medulla of rats with congestive heart failure (CHF), induced by the
placement of an aortocaval fistula. In addition, we examined the
effects of a COX-1 inhibitor (piroxicam), COX-2 inhibitor (nimesulide),
and nonselective COX inhibitor (indomethacin) at a dose of 5 mg/kg, on
intrarenal blood flow by laser Doppler flowmetry. COX-1 and COX-2 mRNAs
were abundantly expressed in the renal medulla of control and CHF rats
and only minimally in the cortex. Moreover, both RT-PCR (32-36
cycles) and Western blot techniques revealed upregulation of medullary
COX-2, but not of COX-1, in rats with advanced heart failure. In line
with these findings, all three tested COX inhibitors provoked
significant and sustained decreases (
20%) in medullary
blood flow (MBF), which were similar in magnitude and duration in
control animals. However, in CHF rats, indomethacin produced a greater
reduction in MBF than that obtained with either piroxicam or
nimesulide. Taken together, these results indicate that 1)
both COX-1 and COX-2 are predominantly expressed in the renal medulla
and 2) experimental CHF is associated with selective
overexpression of COX-2. The latter may represent a mechanism aimed at
defending MBF in the face of a decrease in renal perfusion pressure
during the development of CHF.
congestive heart failure; cyclooxygenase; renal hemodynamics; rat
This article has been cited by other articles:
![]() |
B. Bishara, H. Shiekh, T. Karram, I. Rubinstein, Z. S. Azzam, N. Abu-Saleh, S. Nitecki, J. Winaver, A. Hoffman, and Z. A. Abassi Effects of Novel Vasopressin Receptor Antagonists on Renal Function and Cardiac Hypertrophy in Rats with Experimental Congestive Heart Failure J. Pharmacol. Exp. Ther., August 1, 2008; 326(2): 414 - 422. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Ye, H. Zhang, E. Hillas, D. E. Kohan, R. L. Miller, R. D. Nelson, M. Honeggar, and T. Yang Expression and function of COX isoforms in renal medulla: evidence for regulation of salt sensitivity and blood pressure Am J Physiol Renal Physiol, February 1, 2006; 290(2): F542 - F549. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Wang, J. L. Garvin, J. R. Falck, Y. Ren, S. S. Sankey, and O. A. Carretero Glomerular Cytochrome P-450 and Cyclooxygenase Metabolites Regulate Efferent Arteriole Resistance Hypertension, November 1, 2005; 46(5): 1175 - 1179. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Hofacker, O. Coste, H.-V. Nguyen, C. Marian, K. Scholich, and G. Geisslinger Downregulation of Cytosolic Prostaglandin E2 Synthase Results in Decreased Nociceptive Behavior in Rats J. Neurosci., September 28, 2005; 25(39): 9005 - 9009. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Han, H. Inoue, L. C. Flowers, and N. Sidell Control of COX-2 Gene Expression through Peroxisome Proliferator-Activated Receptor {gamma} in Human Cervical Cancer Cells Clin. Cancer Res., October 1, 2003; 9(12): 4627 - 4635. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Zhang, R. Vezza, T. Plappert, P. McNamara, J. A. Lawson, S. Austin, D. Pratico, M. S.-J. Sutton, and G. A. FitzGerald COX-2-Dependent Cardiac Failure in Gh/tTG Transgenic Mice Circ. Res., May 30, 2003; 92(10): 1153 - 1161. [Abstract] [Full Text] [PDF] |
||||
![]() |
U. C. Kopp, M. Z. Cicha, and L. A. Smith Impaired responsiveness of renal mechanosensory nerves in heart failure: role of endogenous angiotensin Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2003; 284(1): R116 - R124. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Hernandez, H. Astudillo, and B. Escalante Angiotensin II stimulates cyclooxygenase-2 mRNA expression in renal tissue from rats with kidney failure Am J Physiol Renal Physiol, April 1, 2002; 282(4): F592 - F598. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |