Biochem/physiol Actions MK 571 is a potent and selective leukotriene D4 (LTD4) antagonist and ABCC multidrug resistance protein 1(MRP1) inhibitor. The cysteinyl leukotrienes (CysLTs), LTC4, LTD4, and LTE4, mediate their actions through two distinct G-protein coupled receptors. LTD4 is the preferred ligand for the CysLT1 receptor, whereas LTC4 and LTD4 bind with approximately equal affinity to the CysLT2 receptor. MK 571 is a selective, orally active CysLT1 receptor antagonist. It blocks the binding of LTD4, but not LTC4, to human and guinea pig lung membranes with Ki values of 0.22 nM and 2.1 nM, respectively. MK 571 effectively blocks LTD4 activation of recombinant human and mouse CysLT1 receptors but is ineffective at blocking LTC4 or LTD4 activation of the recombinant human or murine CysLT2 receptors. It potentially inhibits MRP1 and has been shown to overcome acquired arsenic tolerance. |
Biochem/physiol Actions MK 571 is a potent and selective leukotriene D4 (LTD4) antagonist and ABCC multidrug resistance protein 1(MRP1) inhibitor. The cysteinyl leukotrienes (CysLTs), LTC4, LTD4, and LTE4, mediate their actions through two distinct G-protein coupled receptors. LTD4 is the preferred ligand for the CysLT1 receptor, whereas LTC4 and LTD4 bind with approximately equal affinity to the CysLT2 receptor. MK 571 is a selective, orally active CysLT1 receptor antagonist. It blocks the binding of LTD4, but not LTC4, to human and guinea pig lung membranes with Ki values of 0.22 nM and 2.1 nM, respectively. MK 571 effectively blocks LTD4 activation of recombinant human and mouse CysLT1 receptors but is ineffective at blocking LTC4 or LTD4 activation of the recombinant human or murine CysLT2 receptors. It potentially inhibits MRP1 and has been shown to overcome acquired arsenic tolerance. |