![]() |
|
|
Vol. 292, Issue 2, 752-760, February 2000
Center for Clinical Pharmacology, Departments of Medicine and
Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh,
Pennsylvania.
Adenosine A1 receptor antagonists are being developed for
use as diuretics in the treatment of hypertension, however, there is
relatively little data in hypertensive animal models regarding the
efficacy of these compounds. In addition, some controversy exists
surrounding the role of pertussis toxin (PT)-sensitive G-proteins in
the signaling pathway for receptors acted on by A1
antagonists. Our objectives for this study were 1) to compare the
diuretic, natriuretic, and cardiovascular effects of acute A1 receptor blockade in spontaneously hypertensive (SHR)
and normotensive Wistar-Kyoto rats (WKY); and 2) to determine whether
the diuretic effects are mediated through a PT-sensitive mechanism.
Acute administration of the selective A1 antagonist
1,3-dipropyl-8-cyclopentylxanthine (DPCPX; 10 µg/kg/min) increased
urine output (410 ± 116 and 317 ± 86 µl/30 min/g kidney)
and sodium excretion (90.3 ± 25.6 and 76.8 ± 18.2 µmol/30
min/g kidney) similarly in WKY and SHR, respectively. DPCPX
significantly decreased mean arterial blood pressure in SHR
(
11.4 ± 2.7 mm Hg), but not WKY. Prior treatment with PT (30 µg/kg i.v.) abolished the diuretic response to DPCPX in both SHR and
WKY. In a subsequent experiment in PT-treated Sprague-Dawley rats,
DPCPX failed to evoke a diuretic response, whereas coinfusion of
furosemide with DPCPX induced marked diuresis. Our results indicate
that acute DPCPX administration produces similar natriuretic/diuretic effects in SHR and WKY, with beneficial effects on blood pressure in
SHR. PT abolishes the response to DPCPX, indicating that the natriuretic/diuretic response to DPCPX is mediated via blockade of
A1 receptors linked to tubular sodium transport through
PT-sensitive G-proteins.
This article has been cited by other articles:
![]() |
A. Kulick, C. Panico, P. Gill, and W. J. Welch Low salt intake increases adenosine type 1 receptor expression and function in the rat proximal tubule Am J Physiol Renal Physiol, July 1, 2008; 295(1): F37 - F41. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Vallon, B. Muhlbauer, and H. Osswald Adenosine and kidney function. Physiol Rev, July 1, 2006; 86(3): 901 - 940. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Deng, C. M. Miracle, M. Lortie, J. Satriano, F. B. Gabbai, K. A. Munger, S. C. Thomson, and R. C. Blantz Kidney oxygen consumption, carbonic anhydrase, and proton secretion Am J Physiol Renal Physiol, May 1, 2006; 290(5): F1009 - F1015. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Zhou and C. K. Kost Jr. Adenosine A1 Receptor Antagonist Blunts Urinary Potassium Excretion, but Not Renal Hemodynamic Effects, Induced by Carbonic Anhydrase Inhibitor in Rats J. Pharmacol. Exp. Ther., February 1, 2006; 316(2): 530 - 538. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Rieg, H. Steigele, J. Schnermann, K. Richter, H. Osswald, and V. Vallon Requirement of Intact Adenosine A1 Receptors for the Diuretic and Natriuretic Action of the Methylxanthines Theophylline and Caffeine J. Pharmacol. Exp. Ther., April 1, 2005; 313(1): 403 - 409. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Gao, C. Zhu, and E. K. Jackson alpha 2-Adrenoceptors Potentiate Angiotensin II- and Vasopressin-Induced Renal Vasoconstriction in Spontaneously Hypertensive Rats J. Pharmacol. Exp. Ther., May 1, 2003; 305(2): 581 - 586. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. K. Jackson and R. K. Dubey Role of the extracellular cAMP-adenosine pathway in renal physiology Am J Physiol Renal Physiol, October 1, 2001; 281(4): F597 - F612. [Abstract] [Full Text] [PDF] |
||||