Single nucleotide polymorphism (SNP) of the endothelial nitric oxide synthase (eNOS) gene (Glu298Asp variant) in infertile men with asthenozoospermia.

The objective of this study was to elucidate the missense Glu298Asp polymorphism within exon 7 of the endothelial nitric oxide synthase (eNOS) gene in infertile men with asthenozoospermia and its potential role in sperm motility. In this prospective controlled study conducted in our andrology unit, we investigated the frequency of the 894G>T polymorphism (Glu298Asp variant) within exon 7 of the eNOS gene in 70 infertile men and 60 healthy men. Sperm motion kinetics were assessed with computer-assisted semen analysis. The presence of G>T, a single nucleotide polymorphism (SNP) in exon 7 of the eNOS gene (NCBI SNP cluster rs1799983; GenBank accession number NG_011992; protein accession number NP_000594) was determined by allelespecific polymerase chain reaction followed by restriction fragment length polymorphism analysis. Sequencing analysis was used to confirm the specific genotype. The 894G>T eNOS allele (T) was found at a higher frequency in the patients with asthenozoospermia (60% vs 22.5% in the control group; P = .02). The percentage of progressive motile sperm (grade a + b) was lower in the asthenozoospermic infertile men with the homozygous eNOS (TT) genotype than in the wild-type eNOS (GG) (P = .02) and heterozygous eNOS (GT) genotypes (P = .01). However, the percentage of progressive motile sperm (grade a + b) was higher in the wild-type vs mutant eNOS (TT) (P = .03) and heterozygous eNOS (GT) genotypes (P = .04). Our findings suggest that the T allele encoding for aspartic acid of the eNOS (Glu298Asp) gene may contribute to poor sperm motility.

Free thiols in human spermatozoa: are Na+/K+-ATPase, Ca2+-ATPase activities involved in sperm motility through peroxynitrite formation?

The aim of the present study was to measure free thiols content, Na(+)/K(+)-ATPase and Ca(2+)-ATPase activities in human spermatozoa of asthenozoospermic patients and normospermic donors, and evaluate any influence on kinetic sperm features, as well as correlation with peroxynitrite. In fact, membrane integrity and its composition are the basic characteristics of the sperm membrane; thus, it is evident that its composition is an important factor for membrane functions that can be modified upon oxidation. A total of 70 infertile patients affected by idiopathic asthenozoospermia and 25 normal fertile donors were enrolled. Control spermatozoa exhibited Na(+)/K(+)-ATPase, and Ca(2+)-ATPase activities, cytoplasmic Ca(2+) concentration and free -SH content significantly higher than those of asthenozoospermic patients (P < 0.0001). Moreover, positive associations were found between Na(+)/K(+)-ATPase and Ca(2+)-ATPase activities and total sperm motility and sperm kinetic features, whereas negative associations were found between peroxynitrite and Na(+)/K(+)-ATPase and Ca(2+)-ATPase activities, and total SH content. Peroxynitrite is able to reduce Na(+)/K(+)-ATPase and Ca(2+)-ATPase activities and intracellular Ca(2+) concentration, through possible depletion of free thiols content. Decrease in motility and loss of sperm function in idiopathic asthenozoospermia can be attributed to these sulphydryl groups, important entities of the sperm membrane.

Coenzyme Q10 treatment in infertile men with idiopathic asthenozoospermia: a placebo-controlled, double-blind randomized trial.

OBJECTIVE: To evaluate the effectiveness of coenzyme Q(10) treatment in improving semen quality in men with idiopathic infertility. DESIGN: Placebo-controlled, double-blind randomized trial. SETTING: Andrology Unit, Department of Internal Medicine, Polytechnic University of Marche, Italy. PATIENT(S): Sixty infertile patients (27-39 years of age) with the following baseline sperm selection criteria: concentration >20 x 10(6)/mL, sperm forward motility <50%, and normal sperm morphology >30%; 55 patients completed the study. INTERVENTION(S): Patients underwent double-blind therapy with coenzyme Q(10), 200 mg/day, or placebo; the study design was 1 month of run-in, 6 months of therapy or placebo, and 3 months of follow-up. MAIN OUTCOME MEASURE(S): Variations in semen parameters used for patient selection and variations of coenzyme Q(10) and ubiquinol concentrations in seminal plasma and spermatozoa. RESULT(S): Coenzyme Q(10) and ubiquinol increased significantly in both seminal plasma and sperm cells after treatment, as well as spermatozoa motility. A weak linear dependence among the relative variations, baseline and after treatment, of seminal plasma or intracellular coenzyme Q(10) and ubiquinol levels and kinetic parameters was found in the treated group. Patients with a lower baseline value of motility and levels of coenzyme Q(10) had a statistically significant higher probability to be responders to the treatment. CONCLUSION(S): The exogenous administration of coenzyme Q(10) increases the level of the same and ubiquinol in semen and is effective in improving sperm kinetic features in patients affected by idiopathic asthenozoospermia.

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. DESIGN: Basic study. SETTING: Andrology Unit, Dept of Internal Medicine and Biochemistry Institute, Polytechnic University of Marche, Italy. PATIENT(S): Sixty-nine infertile patients affected by idiopathic asthenozoospermia and 29 normal fertile donors. INTERVENTION(S): No therapeutic intervention was performed on patients. MAIN OUTCOME MEASURE(S): Production of peroxynitrite (ONOO-) and 3-nitrotyrosine by human spermatozoa; kinetic sperm cells parameters. RESULT(S): 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. CONCLUSION(S): 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.

Role of nitric oxide concentrations on human sperm motility.

Nitric oxide (NO) is a free radical generated from the oxidation of L-arginine to L-citrulline by 3 isoforms of reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent NO synthases. Several data suggest a relevant role in sperm cell pathophysiology, but any conclusive data on its role in spermatozoa motility are still lacking. In the present study, we have correlated NO concentration in semen and kinetic features of sperm cells from normozoospermic fertile donors and infertile patients affected by idiopathic asthenozoospermia. Normozoospermic fertile men exhibited NO concentrations that were significantly lower than those of asthenozoospermic infertile men. A significant linear negative correlation was evident between NO concentration and percentage of total sperm motility. A further significant linear negative correlation was found between NO concentration and spermatozoa kinetic characteristics determined by a computerized analysis (curvilinear and straight progressive velocity). These data suggest that the overproduction of this free radical and the consequent excessive exposure to oxidative conditions have a potential pathogenetic implication in the reduction of sperm motility. The positive role played by NO in spermatozoa capacitation leads us to speculate that such paradoxical involvement in both pathologic and physiologic processes depends on the alternative redox state and relative level of NO.

Coenzyme Q(10) supplementation in infertile men with idiopathic asthenozoospermia: an open, uncontrolled pilot study.

OBJECTIVE: To clarify a potential therapeutic role of coenzyme Q(10) (CoQ(10)) in infertile men with idiopathic asthenozoospermia. DESIGN: Open, uncontrolled pilot study. PATIENT(S): Infertile men with idiopathic asthenozoospermia. INTERVENTION(S): CoQ(10) was administered orally; semen samples were collected at baseline and after 6 months of therapy. MAIN OUTCOME MEASURE (S): Semen kinetic parameters, including computer-assisted sperm data and CoQ(10) and phosphatidylcholine levels. RESULT(S): CoQ(10) levels increased significantly in seminal plasma and in sperm cells after treatment. Phosphatidylcholine levels also increased. A significant increase was also found in sperm cell motility as confirmed by computer-assisted analysis. A positive dependence (using the Cramer's index of association) was evident among the relative variations, baseline and after treatment, of seminal plasma or intracellular CoQ(10) content and computer-determined kinetic parameters. CONCLUSION(S): The exogenous administration of CoQ(10) may play a positive role in the treatment of asthenozoospermia. This is probably the result of its role in mitochondrial bioenergetics and its antioxidant properties.