TABLE 6

Dissociation constants for steroidal antagonists of activator-induced calcium influx in human sperm

OpenerAntagonistSchildLeff-Dougall
pKB
PROGMPA6.19 ± 1.756.16 ± 0.39
LNG6.80 ± 0.105.47 ± 0.23
ALDO5.38 ± 0.275.46 ± 0.16
PGE1MPA5.38 ± 0.596.00 ± 0.26
LNG3.36 ± 0.415.50 ± 0.11
ALDO3.14 ± 0.955.22 ± 0.20
l-SireninMPA5.22 ± 0.335.20 ± 0.20
LNG4.25 ± 0.235.07 ± 0.05
ALDO4.82 ± 1.035.19 ± 0.16
  • The Schild pKB values (mean ± standard error) were obtained using the EC50 values corresponding to the pEC50 values listed in Table 5 derived from 3–8 independent experiments. For all Schild analyses, the slopes of the regression lines had values of 1.0 within the 95% CI. The Leff-Dougall pKB values (mean ± SD) were obtained using the IC50 values corresponding to the pIC50 values listed in Table 4 derived from 5–12 independent experiments.