SIZP mediated intracellular calcium release profile in capacitated human sperm in presence or absence of pharmacological inhibitors of L- and T-type VOCCs. Fluo-3/AM labelled capacitated human sperm (1 × 106) were pre-incubated with either L- type VOCC inhibitor, Verapamil (10 μM) or T-type VOCC inhibitor, pimozide (20 μM), for 10 minutes and then exposed to SIZP (~5 zonae) at 0 seconds. Changes in intracellular calcium levels (nM; y-axis) have been plotted as a function of time (seconds; x-axis) for ~10 min. Blue line represents SIZP mediated calcium increase profile whereas pink and green lines represent SIZP mediated calcium release profile after prior treatment of labelled sperm with Pimozide and Verapamil respectively. Values are presented as Δ [Ca2+]i obtained by subtracting the respective mean resting [Ca2+]i values preceding SIZP addition from the peak [Ca2+]i.