Yuyama H, Sanagi M, Koakutsu A, Mori M, Fujimori A, Harada H, Sudoh K, Miyata K. Pharmacological characterization of YM598, an orally active and highly potent selective endothelin ET(A) receptor antagonist.
Eur J Pharmacol 2004;
478:61-71. [PMID:
14555186 DOI:
10.1016/j.ejphar.2003.08.031]
[Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We describe here the pharmacology of (E)-N-[6-methoxy-5-(2-methoxyphenoxy)[2,2'-bipyrimidin]-4-yl]-2-phenylethenesulfonamide monopotassium salt (YM598), a novel selective endothelin ET(A) receptor antagonist synthesized through the modification of the ET(A)/ET(B) non-selective antagonist, bosentan. YM598 inhibited [125I]endothelin-1 binding to cloned human endothelin ET(A) and ET(B) receptor, with K(i) of 0.697 and 569 nM, and inhibited endothelin-1-induced increases in intracellular Ca(2+) concentration in human and rat endothelin ET(A) receptor. YM598 also inhibited endothelin-1-induced vasoconstriction in isolated rat aorta with a pA(2) value of 7.6. In vivo, YM598 inhibited the pressor response to big endothelin-1, a precursor peptide of endothelin-1. DR(2) values of YM598 in pithed rats were 0.53 mg/kg, i.v. and 0.77 mg/kg, p.o., and its antagonism in conscious rats was maintained for more than 6.5 h at 1 mg/kg, p.o. In contrast, YM598 had no effect on the sarafotoxin S6c-induced depressor or pressor responses. YM598 showed not only superior antagonistic activity and higher-selectivity for endothelin ET(A) receptor in vitro, but at least a 30-fold higher potency in vivo than bosentan. In conclusion, YM598 is a potent and orally active selective endothelin ET(A) receptor antagonist.
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