Abstract

Oxygen radical generation is known to be detrimental to sperm function, especially motility, through the lipid peroxidation of the membranes. Generation of reactive oxygen species can be induced by leukocyte contamination, sperm centrifugation and the presence of abnormal spermatozoa with excess residual cytoplasm. This study aims to evaluate the effect on sperm motility of incubation in an antioxidant-containing solution, during liquefaction and centrifugation. Thirty semen samples were each divided into two equal parts: one mixed with Tyrode's solution, the other with a salt solution containing antioxidants (Sperm-Fit®; Ellios Bio-Media, Paris, France). All the procedures were identical in the two groups. The ratio of leukocytes to spermatozoa was significantly correlated with the motility after liquefaction and after a 24 h incubation in routine in-vitro fertilization (IVF) medium and with the number of motile spermatozoa recovered after Percoll preparation. Moreover, when this ratio was ≥ 0.2, all motility parameters were lowered. Incubation with Sperm-Fit® allowed a higher percentage of motility after Percoll preparation when the ratio was ≥ 0.2 (48 ± 5% versus 41 ± 6% for Sperm-Fit® and Tyrode's solution respectively; P < 0.05) and a greater number of motile spermatozoa recovered after Percoll preparation, whatever the ratio (3.2 ± 1.0 × 106 versus 2.4 ± 0.7 × 106 for Sperm-Fit® and Tyrode's solution respectively when ratio ≥0.2; 18.1 ± 3.4 × 106 versus 14.4 ± 2.9 × 106 for Sperm-Fit® and Tyrode's solution respectively when ratio <0.2; P < 0.05). These results show that incubation with antioxidants during liquefaction and centrifugation increases recovery of motile spermatozoa.