Table 1

Comparison of efficacies of agonists and antagonists at CysLT1and HPN321 (CysLT2) receptors

CysLT1HPN321
AgonistEC50 (nM)EC50(nM)
 LTC4 43  ± 48.9  ± 1.4
 LTD4 0.9  ± 0.14.4  ± 0.2
 LTE4 104  ± 6293  ± 37
 BAY u9773>10,00092  ± 15
AntagonistIC50(nM)1-a IC50(nM)1-a
 BAY u9773440  ± 182300  ± 92
 Zafirlukast0.261-b >1000
 Montelukast2.31-b >5000
 MK-57110.41-c >1000
 LY-17883ND>5000

Calcium mobilization assays were done as described underExperimental Procedures. Data are expressed as the mean ± S.E.M. (n = 3).

    • ↵1-a  IC50 values were determined relative to a 10 nM LTD4 stimulation.

    • ↵1-b  Sarau et al., 1999

    • ↵1-c  Lynch et al., 1999

    • ND, not determined.