Table 1.

Physiological and pathological effects of reactive nitrogen species (RNS) on male fertility.

Type(s) of RNS	Concentration	Experimental Model	Physiological and Pathological Effects	Reference(s)
TnNOS	-	Human	Aids in the process of steroidogenesis	[19,20]
eNOS	50–100 nM	Human	Aberrant patterns of sperm eNOS expression associated with decreased sperm motility (r = −0.46; p < 0.05)	[21,22]
iNOS	>1 mM	Human	Structural association with various tight junction-proteins, including actin, occludin, vimentin, and α-tubulin, vital in modulating the Sertoli cells tight junctions maintaining the BTB	[14]
SNP	(i). 0.25–2.5 mM (ii). 10−6 to 10−4 M	Human	NO induced decreased in sperm motility (p < 0.01) and viability (p < 0.05). Reduction of sperm motility in a dose- and time-dependent manner by SNP. Sperm progressive motility, and concentration of motile cells also reduced by all SNP doses (p < 0.005)	[23,24,25]
SNAP	0–1.2 nmol/106 spermatozoa	Human	A positive correlation was seen between the concentrations of NO and the percentage of immotile spermatozoa (p < 0.01).	[25]

BTB—Blood-testes barrier, eNOS—Endothelial nitric oxide synthase, iNOS—Inducible nitic oxide synthase, SNAP—S-nitroso-N-acetylpenicillamine, SNP- Sodium nitroprusside, TnNOS -Testis specific neuronal nitric oxide synthase.