The production of peroxynitrite by human spermatozoa may affect sperm motility through the formation of protein nitrotyrosine.
OBJECTIVE
To detect peroxynitrite and 3-nitrotyrosine production in human spermatozoa of asthenozoospermic infertile patients and normospermic donors, and evaluate any influence on kinetic sperm features.


METHODS
Basic study.


METHODS
Andrology Unit, Dept of Internal Medicine and Biochemistry Institute, Polytechnic University of Marche, Italy.


METHODS
Sixty-nine infertile patients affected by idiopathic asthenozoospermia and 29 normal fertile donors.


METHODS
No therapeutic intervention was performed on patients.


METHODS
Production of peroxynitrite (ONOO-) and 3-nitrotyrosine by human spermatozoa; kinetic sperm cells parameters.


RESULTS
Normospermic fertile donors exhibited ONOO- concentrations significantly lower than those of asthenozoospermic infertile men (9.11 +/- 3.37 vs. 27.46 +/- 5.77 nmol/10(6) cells); confocal microscopy showed that ONOO- was more evident in spermatozoa of patients than in healthy donors. Moreover, a significant negative correlation was evident between ONOO- concentration and total sperm motility, curvilinear velocity (VCL), straight progressive velocity (VSL), and linearity coefficient. Finally, an increase was found in the nitration of the tyrosine residues in asthenozoospermic samples compared to controls.


CONCLUSIONS
Spontaneous tyrosine nitration occurs in human spermatozoa. This post-translational protein modification is enhanced by an overproduction of peroxynitrite, which is more evident in asthenozoospermic infertile patients when compared with normospermic fertile donors. Motility parameters are negatively affected, suggesting that ONOO- may be involved in defective sperm function.
Institute of Biochemistry, School of Medicine, Polytechnic University of Marche, Ancona, Italy.
Arianna
A
Vignini
Laura
L
Nanetti
Eddi
E
Buldreghini
Cinzia
C
Moroni
Giuseppe
G
Ricciardo-Lamonica
Franco
F
Mantero
Marco
M
Boscaro
Laura
L
Mazzanti
Giancarlo
G
Balercia
D000328:Adult; D006801:Humans; D007248:Infertility, Male / Q000378:metabolism*; D008297:Male; D030421:Peroxynitrous Acid / Q000032:analysis / Q000096:biosynthesis*; D013081:Sperm Motility / Q000502:physiology*; D013094:Spermatozoa / Q000737:chemistry / Q000378:metabolism*; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000096:biosynthesis
D030421:Peroxynitrous Acid; C002744:3-nitrotyrosine; D014443:Tyrosine