Figure 3.

U73343 and U73122 block the MTx-induced AR in human (a) and mouse (b) spermatozoa. After capacitation, the AR was induced with 5 nmol l⁻¹ MTx in the presence or absence of U73122 or U73343 (10 µmol l⁻¹ each). The ARI values for the control (solvent alone) or the inhibitors alone are also shown (black bars). The data represent the mean±SEM from six independent experiments and were normalized as described in the section on ‘Materials and methods' (***P<0.001, **P<0.01). AR, acrosome reaction; ARI, acrosome reaction index; MTx, maitotoxin.