Table 2 Effects of nitric oxide levels on sperm parameters

Motility

50-100 nM eNOS

1. Aberrant patterns of sperm eNOS expression associated with decreased sperm motility (r = −0.46; p<.05).

[26]

2. At low concentrations, NO improved post- thaw sperm motility.

Motility

10^-5 M L-NAME

1. In the presence of NO inhibitor, L-NAME, the percentage progressive motility, average path velocity, straight linear velocity, and curvilinear velocity were significantly reduced after 30 min.

[40]

Motility

SNP levels in infertile males with leukocytospermia (6.58 ± 0.5.6 μM); infertile males without leukocytospermia (5.51 ± 0.25 μM) vs. Control (3.91 ± 0.16 μM)

1. There was a significant correlation between the NO₂ concentration and sperm motility (r = 0.33; p<0.0005).

[41]

2. SNP reduced the sperm motility in a dose- and time-dependent manner (p<0.0001).

Motility

0-3 nmol x 10⁶ NO

1. Higher NO concentrations result in lower total percentage of sperm motility (p<0.0007).

[38]

Motility

> 20 x 10⁶ sperm/mL

1. Addition of SNP decreased mouse sperm motility, without any change in hyperactivation.

[42]

2. The NOS inhibitor, L-NAME, and the NO scavenger, methylene blue inhibited sperm motility (p<.0.005).

Motility

GSNO (100 nmol/L)

1. A 20 minute incubation of nitric oxide with NO releasing compounds (GSNO, PTIO, ODQ, 8-Br-cGMP, and Rp-8-Br-cGMPSs) did not alter the progressive motility of human sperm (p<0.05).

[39]

PTIO (100μmol/L)

ODQ (50μmol/L)

8-Br-cGMP (1mmol/L)

Rp-8-Br-cGMPSs (10μmol/L)

Motility

50 nM and 100 nM SNP

1. The maintenance of percent motility at 3 hours post-thaw was significantly improved in SNP treated samples (p<0.05)

[43]

Motility

5μM GSNO

1. The NO donor, GSNO, significantly increased progressive motility (77, 78, and 78% vs 66, 65, and 62% of the control)

[44]

2. A similar effect was obtained with the NO donor sperm,NONOate, after 30 and 60 min.

Motility

SNP (0.25-2.5 mM)

1. NO decreased sperm motility (r = 0.740; p<0.01).

[35]

SNAP (0.012-.6 mM)

Motility

SNAP 0-1.2 nmol/10⁶ spermatozoa

1. A positive correlation was seen between the concentrations of NO and the percentage of immotile spermatozoa (p<0.01).

[24, 25]

Motility

10^-6 to 10^-4 M SNP

1. The percentage of motile sperm, progressive motility, and concentration of motile cells were all significantly reduced with all doses of SNP (p<0.005).

[45]

Morphology

Good morphology ≥ or equal to 14% normal sperm.

1. No significant difference was observed between NO production and sperm morphology (good or poor).

[39]

Poor morphology <14% normal

2. No association was found between poor semen quality and elevated levels of basal NO production.

Morphology

Good morphology ≥ or equal to 14% normal sperm

1. A positive correlation was shown between concentrations of seminal plasma NO and defects in sperm morphology (r = 0.4; p<0.05).

[46]

Poor morphology <14% normal

2. Low levels of NO within the seminal plasma has been associated with defects in sperm morphology (r = 0.4; p<0.05).

Viability

10^-6-10^-4 M SNP

1. Sperm viability in SNP treated sperm did not differ significantly from that of control sperm (p>0.05).

[45]

Viability

SNP (0.25-2.5 mM)

1. NO has been found to reduce sperm viability (p<0.05).

[35]

S-nitroso-N-acetylpenicillamine (SNAP: 0.012-0.6 mM)

Viability

10^-5 M L-NAME

1. Sperm viability did not decrease in the presence of L-NAME, a nitric oxide synthase inhibitor.

[47]

Viability

50-100 nM NO

1. At low concentrations, NO improves post-thaw sperm viability.

[36]

Viability

>40 x 10⁶ sperm/mL

1. NO released by SNP has been shown to play a role in the maintenance of sperm viability after cryopreservation.

[38]

Viability

10^-4M SNP

1. NO has been shown to decrease sperm viability

[45]