title: The effect of incubation periods under 95% oxygen on the stimulated acrosome reaction and motility of human spermatozoa.
abstract: Human sperm samples were prepared on a 30% Percoll gradient and reactive oxygen species (ROS) production was measured. In samples that generated ROS incubation under 95%O2:5%CO2 for 30 min decreased the proportion of spermatozoa capable of the stimulated acrosome reaction by 40% in comparison to samples incubated under 95%N2:5%CO2 (P< 0.001, repeated measures analysis of variance), but the degree of inhibition did not increase after more prolonged incubation periods (up to 6 h). The addition of the antioxidants catalase and superoxide dismutase prevented the inhibitory effect of 95%O2:5%CO2. Leukocyte removal from samples prior to 95%O2:5%CO2 incubation preserved the ability of the spermatozoa to acrosome react. Sperm motility parameters were less affected by 95%O2:5%CO2 but track velocity was 64.1 microm/s+/-1.96 after 2 h incubation under 95%N2:5%CO2 compared with 54.7 microm/s+/-1.41 after 2 h incubation under 95%O2:5%CO2 (P < 0.05, repeated measures analysis of variance). Sperm samples that did not generate detectable ROS were not affected by 95%O2:5%CO2. The toxic effects of incubation under 95%O2:5%CO2 on human spermatozoa result from increased endogenous ROS production, mostly from leukocytes. High ROS levels inhibit sperm function, with the stimulated acrosome reaction being more susceptible than motility parameters.
authors.affiliation: University of Bristol, Division of Obstetrics and Gynaecology, St Michael's Hospital, UK.
authors.forename: K
authors.initials: K
authors.lastname: Whittington
authors.forename: W C
authors.initials: WC
authors.lastname: Ford
mesh_terms: D020101:Acrosome Reaction; D000328:Adult; D006801:Humans; D008297:Male; D010100:Oxygen; D017382:Reactive Oxygen Species; D012662:Semen Preservation / Q000379:methods*; D013081:Sperm Motility; D013094:Spermatozoa
chemical_list: D017382:Reactive Oxygen Species; D010100:Oxygen