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Drug Monitoring and Toxicology |
1
Montreal Heart Institute, Department of Laboratory Medicine, 5000 Belanger Street East, Montreal, Quebec, H1T 1C8 Canada.
Departments of
2
Medicine and
3
Physiology,
McGill University, Montreal, Quebec, H1T 1C8 Canada.
a Author for correspondence. Fax (514) 593-2577; e-mail jhunte{at}is.RVH.McGill.CA.
Orally active nonpeptide antagonists of endothelin (ET) receptors may prove beneficial in the treatment of cardiovascular and renal disease. The pharmacodynamics and pharmacokinetics of these drugs are not sufficiently known, and practical methods for their analysis have not been developed. We describe a simple, sensitive, and reproducible radioreceptor assay (RRA) for LU135252, a selective antagonist of the ETA receptor, using porcine aortic smooth muscle membranes as the acceptor and 125I-endothelin-1 as the ligand. With methanol extraction of plasma and urine samples, recovery of LU135252 ranged from 79% to 91% at 601000 nmol/L. The logit-log transformed calibration curves constructed with LU135252 added to plasma or to urine were linear (r = 0.993 ± 0.005, n = 11) in the range from 18.7 to 2400 nmol/L. The detection limit with plasma- and urine-based calibration curves was 19 nmol/L. The interassay coefficient of variation was 12.6% at 70 nmol/L (n = 9) and 6.5% at 590 nmol/L (n = 9). Endothelin-1 did not interfere in the RRA at pathophysiologically and clinically relevant concentrations [up to 15 pmol/L (40 pg/mL)]. When LU135252 was added to plasma, the signal was completely stable after storage for 1 week at 4 °C, although there was a modest loss of the signal after 24 h at room temperature. The practical performance of this RRA was then tested in plasma samples obtained from (a) rats after a single oral administration of LU135252, (b) from coronary-ligated rats chronically treated with LU135252, and (c) in plasma and urine samples obtained from dogs during intrarenal infusion of LU135252.
The following articles in journals at HighWire Press have cited this article:
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B. J Epstein Efficacy and Safety of Darusentan: A Novel Endothelin Receptor Antagonist Ann. Pharmacother., July 1, 2008; 42(7): 1060 - 1069. [Abstract] [Full Text] [PDF] |
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B. Petersen, M. Deja, R. Bartholdy, B. Donaubauer, S. Laudi, R. C. E. Francis, W. Boemke, U. Kaisers, and T. Busch Inhalation of the ETA receptor antagonist LU-135252 selectively attenuates hypoxic pulmonary vasoconstriction Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2008; 294(2): R601 - R605. [Abstract] [Full Text] [PDF] |
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Q. T. Nguyen, P. Cernacek, M. G. Sirois, A. Calderone, N. Lapointe, D. J. Stewart, and J. L. Rouleau Long-Term Effects of Nonselective Endothelin A and B Receptor Antagonism in Postinfarction Rat: Importance of Timing Circulation, October 23, 2001; 104(17): 2075 - 2081. [Abstract] [Full Text] [PDF] |
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S. Babaei, P. Picard, A. Ravandi, J. C. Monge, T. C. Lee, P. Cernacek, and D. J. Stewart Blockade of endothelin receptors markedly reduces atherosclerosis in LDL receptor deficient mice: role of endothelin in macrophage foam cell formation Cardiovasc Res, October 1, 2000; 48(1): 158 - 167. [Abstract] [Full Text] [PDF] |
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K. AMANN, K. MÜNTER, S. WESSELS, J. WAGNER, V. BALAJEW, S. HERGENRÖDER, G. MALL, and E. RITZ Endothelin A Receptor Blockade Prevents Capillary/Myocyte Mismatch in the Heart of Uremic Animals J. Am. Soc. Nephrol., September 1, 2000; 11(9): 1702 - 1711. [Abstract] [Full Text] |
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