The effects of in vitro cocaine exposure on human sperm motility, intracellular calcium, and oocyte penetration

To determine if cocaine exposure affects human sperm motility, intracellular calcium level, and fertilizing capability. Human semen samples were treated with 1 to 1,000 µM cocaine hydrochloride for up to 2hours in vitro. Sperm motion kinematics were measured by computer-assisted semen analysis (CASA). Spermatozoan intracellular calcium was determined by laser cytometry. The sperm fertilizing capability was assessed using the zona-free hamster oocyte penetration test. After a short exposure (15minutes) to cocaine, the sperm motion kinematic parameters, straight line velocity and linearity, were decreased in the high concentration groups. However, after a longer exposure (2hours) to cocaine, the differences were no longer significant. Cocaine treatment did not alter spermatozoa intracellular calcium levels. Most importantly, human sperm treated with cocaine at a high concentration were fully capable of penetrating zona-free hamster oocytes. Human spermatozoa acutely exposed to high concentrations of cocaine initially demonstrate a decrease in two motion kinematics, straight line velocity and linearity. However, overall, cocaine exposure had no significant effects on sperm motility and fertilizing capability.