alpha-chlorohydrin induced changes in sperm fertilizing ability in the rat: association with diminished sperm ATP levels and motility

In the present study, alpha-chlorohydrin (ACH) (5, 10, 25, 50 and 75 mg/kg, po) was administered to rats and the effects on sperm ATP levels, sperm motility, and the ability of sperm to bind and penetrate rat oocytes were determined. Groups of rats were killed 5 days and 3 h following treatment. At both time points, sperm from ACH-treated rats (>/=10 mg/kg) had significantly lower levels of ATP when diluted in media containing glucose. No diminution of ATP was seen in sperm diluted in phosphate-buffered saline (PBS). Computer analysis of sperm motility indicated that straight-line velocity (VSL) was the most sensitive parameter to ACH treatment and was significantly decreased in rat sperm three hours after ACH exposure (25 mg/kg). A clear drop in percent penetration (35% vs. 85% in control) of zona-free rat oocytes by rat sperm of both ACH groups was observed at 10 mg/kg. Higher dose levels produced no significant further decrease in percent penetration. Overall, the fertilizing ability of sperm was highly sensitive to ACH doses that caused minor but significant changes in sperm ATP levels and no significant changes in motility. These data are consistent with the spermatozoan's need for an uncompromised energy supply to maintain its ability to bind and penetrate the oocyte.