← Back to Knowledge Base

Primary topic: nitric oxide vascular tone pathway

Nitric Oxide and Vascular Tone Pathway: When Circulation Changes Performance and Recovery

This pathway matters when circulation, exercise tolerance, and recovery questions keep resurfacing without a clean explanation.

What this pathway does

The pathway supports endothelial nitric-oxide production, vascular tone, and nutrient delivery under physical or metabolic demand.

Why it matters

It matters because weaker nitric-oxide support can affect performance, circulation, and recovery in ways that overlap with energy and oxidative-stress pathways.

What creates pressure on this pathway

  • lower nitric-oxide production or arginine availability
  • weaker endothelial support under recovery or exercise demand

Validation markers to consider

  • arginine / citrulline context
  • blood pressure
  • endothelial context

Genes and SNPs connected to this pathway

This is about how well your blood vessels tighten and relax. That affects blood pressure and circulation.

Study rows support the SNP/gene claim. The pathway connection comes from the curated gene-to-pathway map.

What may run higher

Your blood vessels may react strongly to stress, sleep loss, or stimulants.

What may work more slowly

Your blood vessels may not relax as well, which can weaken blood flow.

What to check next

Check home blood pressure, resting heart rate, exercise tolerance, lipid markers, glucose markers, kidney function, and oral health.

3mapped genes
3mapped SNPs
5SNP/gene claims
3report eligible
AGXT21 SNPs - 1 claimsShow SNPsOpen gene page
rs373691 claims - 2 study rows

enzyme activity - T

AGXT2 methylarginine and beta-aminoisobutyrate metabolism

Strong

rs37369 T / AGXT2 Ile140 is associated with lower AGXT2 methylarginine and beta-aminoisobutyrate metabolism.

AGXT2 rs37369 T is staged as a reduced-activity aminotransferase allele affecting SDMA and BAIB/BAIBA handling.

Likely effectLower enzyme activity signal
Signal sizeSmall signal
Evidence supportStrong support
Report useIncluded in pathway scoring
Show study evidence
PMCID PMC4797637functional assay - directThe checked SDMA GWAS/functional source reports rs37369 T/C for SDMA and shows AGXT2 T/Ile140 has reduced SDMA-metabolizing activity versus C/Val140 in HEK293 overexpression.PMCID PMC3169529biomarker association - close proxyThe checked metabolic-QTL source reports rs37369 as a likely functional AGXT2 driver for urinary beta-aminoisobutyric acid, with BAIBu increasing with minor-allele copies.
ARG11 SNPs - 1 claimsShow SNPsOpen gene page
rs1048939481 claims - 2 study rows

enzyme activity - AA or compound-heterozygous ARG1 deficiency context

ARG1 arginine hydrolysis activity tendency

Strong

rs104893948 A / ARG1 c.703G>A / p.Gly235Arg is associated with lower arginase 1 arginine-hydrolysis activity and altered arginine availability in recessive or compound-heterozygous contexts.

ARG1 rs104893948 A is staged as a recessive arginase-deficiency allele affecting ARG1 activity, plasma arginine, and nitric-oxide substrate context.

Likely effectLower enzyme activity signal
Signal sizeModerate signal
Evidence supportStrong support
Report useIncluded in pathway scoring
Show study evidence
ClinVar RCV000667889clinical curation - directClinVar maps rs104893948 to ARG1 NM_000045.4:c.703G>A / p.Gly235Arg and classifies the variant-condition record for arginase deficiency as pathogenic with multiple submitters and no conflicts.GeneReviews Arginase Deficiencyclinical curation - directGeneReviews supports arginase deficiency diagnosis through elevated plasma arginine, biallelic ARG1 pathogenic variants, and/or very low red blood cell arginase activity, connecting ARG1 loss to arginine-disposal biomarkers.
NOS31 SNPs - 3 claimsShow SNPsOpen gene page
rs17999833 claims - 9 study rows

enzyme activity - TT

NOS3 enzyme activity

Moderate

rs1799983 TT is associated with reduced NOS3 enzyme activity.

NOS3 rs1799983 is scored as a cautious tendency toward lower endothelial nitric oxide synthase activity for T-containing genotypes, strongest for TT.

Likely effectLower enzyme activity signal
Signal sizeSmall signal
Evidence supportModerate support
Report useIncluded in pathway scoring
Show study evidence
NCBI RefSNP recordidentity only - unknownNCBI RefSNP identifies rs1799983 in NOS3 and annotates the common G and T alleles with the endothelial nitric oxide synthase Glu298Asp protein difference. This record scores the common G/T genotype set for a simplified NOS3 functional tendency.PubMed 17449720functional assay - directJoshi et al. studied human endothelial cells by NOS3 Glu298Asp genotype and found that Asp-variant genotypes had lower nitric oxide metabolite production before and after shear exposure, with altered NOS3 caveolar localization and impaired shear response. This supports a lower NOS3 activity tendency for T-containing genotypes.PubMed 37451608review - directA 2023 systematic review and meta-analysis notes that published studies have reported lower circulating nitric oxide with the NOS3 Glu298Asp polymorphism, while clinical association results vary by ancestry and endpoint. This supports keeping the effect as a cautious enzyme-activity tendency rather than a disease prediction.

enzyme activity - GT

NOS3 enzyme activity

Not used for pathway scoring

rs1799983 GT is associated with reduced NOS3 enzyme activity.

NOS3 rs1799983 is scored as a cautious tendency toward lower endothelial nitric oxide synthase activity for T-containing genotypes, strongest for TT.

Likely effectLower enzyme activity signal
Signal sizeSmall signal
Evidence supportModerate support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only - unknownNCBI RefSNP identifies rs1799983 in NOS3 and annotates the common G and T alleles with the endothelial nitric oxide synthase Glu298Asp protein difference. This record scores the common G/T genotype set for a simplified NOS3 functional tendency.PubMed 17449720functional assay - directJoshi et al. studied human endothelial cells by NOS3 Glu298Asp genotype and found that Asp-variant genotypes had lower nitric oxide metabolite production before and after shear exposure, with altered NOS3 caveolar localization and impaired shear response. This supports a lower NOS3 activity tendency for T-containing genotypes.PubMed 37451608review - directA 2023 systematic review and meta-analysis notes that published studies have reported lower circulating nitric oxide with the NOS3 Glu298Asp polymorphism, while clinical association results vary by ancestry and endpoint. This supports keeping the effect as a cautious enzyme-activity tendency rather than a disease prediction.

enzyme activity - GG

NOS3 enzyme activity

Not used for pathway scoring

rs1799983 GG has no scored directional claim for NOS3 enzyme activity.

NOS3 rs1799983 is scored as a cautious tendency toward lower endothelial nitric oxide synthase activity for T-containing genotypes, strongest for TT.

Likely effectNo clear enzyme signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only - unknownNCBI RefSNP identifies rs1799983 in NOS3 and annotates the common G and T alleles with the endothelial nitric oxide synthase Glu298Asp protein difference. This record scores the common G/T genotype set for a simplified NOS3 functional tendency.PubMed 17449720functional assay - directJoshi et al. studied human endothelial cells by NOS3 Glu298Asp genotype and found that Asp-variant genotypes had lower nitric oxide metabolite production before and after shear exposure, with altered NOS3 caveolar localization and impaired shear response. This supports a lower NOS3 activity tendency for T-containing genotypes.PubMed 37451608review - directA 2023 systematic review and meta-analysis notes that published studies have reported lower circulating nitric oxide with the NOS3 Glu298Asp polymorphism, while clinical association results vary by ancestry and endpoint. This supports keeping the effect as a cautious enzyme-activity tendency rather than a disease prediction.

Where DNA analysis helps

DNA helps identify when vascular-tone support deserves attention before circulation issues are dismissed as too nonspecific.

Example interpretation

Nitric-oxide support may deserve follow-up when circulation and recovery signals align more than the energy-only story suggests.

Suggested validation: arginine / citrulline context.

What to do next

  • use blood-pressure and nitric-oxide context before assuming the pathway is the main issue
  • review NOS3, ARG1, and GCH1 together instead of as separate snippets

Related pages

NOS3

NOS3 nitric oxide gene

ARG1

ARG1 gene DNA analysis

Slow metabolism

slow metabolism genetics

Arginine, citrulline, and nitric oxide

Arginine, citrulline, and nitric oxide DNA follow-up

How accurate are DNA metabolism reports?

how accurate are DNA metabolism reports

Best DNA test for metabolism

best DNA test for metabolism

Get the full report

Use your DNA file to see which pathways may be worth validating first.