Effect of 2',4'-dichlorobenzamil hydrochloride, a Na(+)-Ca(2+) exchange inhibitor, on human spermatozoa.

The present study is aimed to investigate the contact spermicidal efficacy of 2',4'-dichlorobenzamil hydrochloride (DBZ), a Na(+)-Ca(2+) exchange inhibitor, on ejaculated human spermatozoa. The drug produced a dose- and time-dependent spermicidal action on human spermatozoa. A concentration of 4 mM produced total loss of sperm viability within 1 min of addition to total semen. On the other hand, a similar action on spermatozoa separated from semen was noted at 0.5 mM concentration. The loss of spermatozoal viability was accompanied with an increase in intracellular Ca(2+). Sperm revival testing with glucose suggested a spermicidal rather than a spermiostatic action.