Background:

Montelukast Sodium (MK-0476) is a selective, reversible antagonist of leukotriene receptor with the Ki values of 0.52nM in U937 cell [1].

Montelukast Sodium has been reported to inhibit leukotriene D4 receptor specific binding in U937 cell, guinea pig lung and sheep lung with the Ki values of 0.52nM, 0.18nM and 4nM, respectively. In addition, Montelukast Sodium has also shown the inhibitory effect with the IC50 of 10mM for leukotriene C3 in U937 cell membranes and 40mM for leukotriene B4 in THP-1 cell membranes. Apart from these, after oral treatment of Montelukast Sodium, it has been revealed to suppress leukotriene D4 receptor induced bronchoconstriction in conscious squirrel monkeys with ED50 value of 0.03±0.001mg/kg [1].

参考文献:
[1] Jones TR1, Labelle M, Belley M, Champion E, Charette L, Evans J, Ford-Hutchinson AW, Gauthier JY, Lord A, Masson P, et al. Pharmacology of montelukast sodium (Singulair), a potent and selective leukotriene D4 receptor antagonist. Can J Physiol Pharmacol. 1995 Feb;73(2):191-201.