Flow-sorted ram spermatozoa are highly susceptible to hydrogen peroxide damage but are protected by seminal plasma and catalase

Abstract

To determine whether flow sorting increased the susceptibility of spermatozoa to reactive oxygen species (ROS), ram semen was either diluted with Tris medium (100 106 spermatozoa mL-1; D) or highly diluted (106 spermatozoa mL-1) before being centrifuged (DC) at 750g for 7.5 min at 21°C or flow-sorted (S) before cryopreservation. Thawed spermatozoa were resuspended in graded concentrations of hydrogen peroxide to induce oxidative stress. In Experiment 1, following exposure to 30 or 45μM hydrogen peroxide (H2O2), the total motility (%) of DC (41.0 ± 7.3 or 25.7 ± 6.7, respectively) and S spermatozoa (33.8 ± 6.3 or 20.1 ± 6.3, respectively) was lower (P < 0.001) than that of D spermatozoa (58.7..