THE EFFECTS OF LIGNOCAINE ON HUMAN SPERM MOTILITY

Objective. The purpose of this study was to assess the motility of human sperm incubated with various concentrations of lignocaine. Methods: Eleven semen samples with a sperm density greater-than-or-equal-to 20 x 10(6) ml and progressive motility greater-than-or-equal-to 40% were prepared using a swim-up technique. Aliquots from each sample were incubated for 4 hr under capacitating conditions with lignocaine concentrations of 100, 10, 1, and 0.1-mu-g/ml and without additional lignocaine as a control. Digital computerized motion analysis was performed on all samples at 1, 2, and 4 hr after the addition of lignocaine. Results: After 2 hr of incubation a significant (P < 0.05) increase in the percentage of sperm with a curvilinear velocity >100-mu-m/sec was observed in those samples incubated with 100-mu-g/ml lignocaine. This stimulatory effect was no longer apparent after a further 2 hr of incubation. No other significant changes were identified in any of the motility parameters examined. Conclusions: No adverse effects on human sperm motility were identified during incubation with low concentrations of lignocaine. A transient stimulatory effect was observed at a lignocaine concentration of 100-mu-g/ml.