E. Delamirande et C. Gagnon, IMPACT OF REACTIVE OXYGEN SPECIES ON SPERMATOZOA - A BALANCING ACT BETWEEN BENEFICIAL AND DETRIMENTAL EFFECTS, Human reproduction, 10, 1995, pp. 15-21
Reactive oxygen species (ROS) have beneficial or detrimental effects o
n sperm functions depending on the nature and the concentration of the
ROS involved, as well as the moment and the location of exposure, Exc
essive generation of ROS in semen, mainly by neutrophils but also by a
bnormal spermatozoa, could be a cause for infertility, Hydrogen peroxi
de is the primary toxic ROS for human spermatozoa. Low concentrations
of this ROS do not affect sperm viability but cause sperm immobilizati
on mostly via depletion of intracellular ATP and the subsequent decrea
se in the phosphorylation of axonemal proteins. High concentrations of
hydrogen peroxide induce lipid peroxidation and result in cell death.
On the other hand, the superoxide anion appears to play a major role
in the development of hyperactivation and capacitation, The observatio
ns that: (i) exogenously generated superoxide anions induce hyperactiv
ation and capacitation; (ii) capacitating spermatozoa themselves produ
ce elevated concentrations of superoxide anion over prolonged periods
of time; and (iii) removal of this ROS by superoxide dismutase prevent
s sperm hyperactivation and capacitation induced by various biological
fluids, stress the importance of the superoxide anion in these proces
ses.