SIZP mediated induction of acrosome reaction in capacitated human sperm in presence or absence of pharmacological inhibitors of L- and T-type VOCCs. Capacitated human sperm (1 × 106) pre-incubated for 10 min at 37°C in presence of 5% CO2, with L-type VOCC inhibitors (Nifedipine, Verapamil), T-type VOCC inhibitors (Pimozide, Mibefradil) or respective vehicle controls (Panels 2a and 2b respectively) were subsequently incubated with SIZP (~5 zonae). After 60 min incubation at 37°C in presence of 5% CO2, sperm samples were analyzed for their acrosomal status by TRITC-PSA staining as described in Methods. Y-axis represents percent induction of acrosomal exocytosis calculated by dividing the number of acrosome-reacted sperm by total number of sperm counted and multiplied by 100. Values are Mean ± SEM of six different experiments using semen samples from at least six different male donors. Calcium ionophore A23187 (10 μM) was used as a positive control in the experiment. Asterisk (*) represents p < 0.05 with respect to the solvent control and hash (#), p < 0.05 with respect to SIZP mediated induction of acrosome reaction.