REACTIVE OXYGEN SPECIES IN SEMEN OF INFERTILE PATIENTS - LEVELS OF SUPEROXIDE DISMUTASE-LIKE AND CATALASE-LIKE ACTIVITIES IN SEMINAL PLASMAAND SPERMATOZOA
A. Zini et al., REACTIVE OXYGEN SPECIES IN SEMEN OF INFERTILE PATIENTS - LEVELS OF SUPEROXIDE DISMUTASE-LIKE AND CATALASE-LIKE ACTIVITIES IN SEMINAL PLASMAAND SPERMATOZOA, International journal of andrology, 16(3), 1993, pp. 183-188
Reactive oxygen species (ROS) can be detected in the semen of 40% of i
nfertile men, whereas none is detected in semen from normal men. The R
OS detected in semen are a reflection of the imbalance between ROS pro
duction and degradation. The aim of the present study was to determine
whether a lowered scavenging capacity or an increased production of R
OS was responsible for the ROS detected in semen samples from infertil
e men. Two activities were investigated: (1) catalase-like activity, w
hich is responsible for the degradation of H2O2, and (2) superoxide di
smutase-like (SOD-like) activity which is responsible for the degradat
ion of .O2-. Catalase-like and SOD-like activities were found in whole
seminal plasma, in dialyzed seminal plasma (> 12 kD), in an ultrafilt
rate of seminal plasma (< 5 kD) and in spermatozoa. There was no signi
ficant difference in the SOD-like activities measured in spermatozoa,
or in seminal plasma (whole or fractionated) from samples that did or
did not produce ROS. SOD-like activity originated mostly from the high
molecular weight components of seminal plasma. However, the catalase-
like activity of whole seminal plasma and of spermatozoa was significa
ntly greater (P = 0.01) in those samples that produced ROS as compared
to those that did not. The catalase-like activity in dialyzed seminal
plasma, and an ultrafiltrate of seminal plasma from semen samples tha
t did or did not produce ROS were not statistically different. The cat
alase-like activity of the seminal plasma originated equally from high
and low molecular weight components. In conclusion, the data suggest
that the ROS detected in the semen of infertile patients are likely du
e to increased ROS production rather than to decreased ROS scavenging
capacity.