Table 2.
Effects of nitric oxide levels on sperm parameters
| Sperm parameter | Concentration of sperm or NO/NOS/NO inhibitor/releaser | Results | Ref. |
|---|---|---|---|
|
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] |
L-NAME = NG-nitro-L-arginine methyl ester.
SNAP = S-nitroso-N-acetylpenicillamine.
SNP = Sodium Nitroprusside.
GSNO = S-Nitrosoglutathione.
PTIO = 2-Phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl.
ODQ = 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one.
8-Br-cGMP = 8-Bromoguanosine- 3', 5'- cyclic monophosphate.
Rp-8-Br-cGMPSs = 8-Bromoguanosine- 3', 5'- cyclic monophosphorothioate, Rp-isomer.