Figure 4.

Effects of T channel antagonists on sperm acrosome reactions. (A) Occurrence (%) of acrosome reactions following sperm adhesion to zonae pellucidae for 1 and 60 min in control medium (•) or in medium supplemented with d-glucose (1 mM; ○), amiloride (500 μM; ▵), or pimozide (0.5 μM; ▿). Data repesent the mean (±SEM) of four experiments using 72–135 zonae pellucidae for each experimental condition and with 29–34 sperm bound per zona pellucida in all treatments. (B) Sperm bound to zona pellucida in control medium for 60 min. (×1000; zona pellucida staining subtracted.) Most sperm are acrosome reacted and do not exhibit dark staining in the apical head (large arrowheads). (C) Sperm bound to zona pellucida for 60 min in the presence of 0.5 μM pimozide. Most sperm fail to acrosome react, as indicated by a stained region in the apical head (small arrowheads).