M. Shekarriz et al., EFFECTS OF TIME AND SPERM CONCENTRATION ON REACTIVE OXYGEN SPECIES FORMATION IN HUMAN SEMEN, Archives of andrology, 34(2), 1995, pp. 69-75
Although generally accepted standards exist for routine semen analysis
, recent methods of assessing reactive oxygen species (ROS) in human s
emen lack a standardized protocol. The purpose of this study was to in
vestigate (1) the relationship between ROS level and the time interval
between semen collection and analysis, and (2) the effect of sperm co
ncentration on the level of ROS formation. Semen specimens from men (n
= 40) consulting for infertility treatment were divided in two groups
: in 20, routine semen analysis was performed and ROS formation evalua
ted at 1, 3, 5, and 24 h after semen collection; in the other 20, ROS
formation was evaluated at four sperm concentrations (60, 30, 15, and
7.5 x 10(6)/mL). White blood cell (WBC) concentration was assessed bef
ore ROS measurement using a myeloperoxidase staining technique (Endtz
test). ROS level was measured by a chemiluminescence method. ROS forma
tion decreased significantly over time. The mean ROS level 343.4 (1 h)
, 133.5 x 10(4) cpm (3 h, p = .004), 66.0 x 10(4) cpm (5 h, p less tha
n or equal to .001), and 22.2 x 10(4) cpm (24 h, p less than or equal
to .001), respectively. In the first group of 20 specimens, 14 were po
sitive for ROS formation at 1 h after collection, and 4 of these were
positive for the Endtz test (>1 x 10(6) WBC/mL). The number of ROS-pos
itive specimens after 3, 5, and 24 h was eight, six, and two, respecti
vely. In the second group, eight patients were positive for ROS format
ion at 1 h after collection. ROS levels were significantly lower at sp
erm concentrations of 15 x 10(6)/mL and 7.5 x 10(6)/mL as compared to
30 x 10(6)/mL or 60 x 10(6)/mL (p < .001). The results indicate that R
OS level changes significantly at various sperm concentrations prepare
d from the same specimen. This change emphasizes the importance of the
sperm concentration as a factor when comparing ROS levels between dif
ferent positive specimens or between repeated measurements. Secondly,
the ROS should be measured within 1 h after semen collection to evalua
te the actual incidence of ROS formation.