Does eNOS Gene Polymorphism Play a Role in the Maintenance of Basal Vascular Tone in the Choroid or Optic Nerve Head?

Status

Terminated

Phases

Early Phase 1

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00708357

Enrollment

Registered

2008-07-02

Start date

2005-05-31

Completion date

2013-01-31

Last updated

2014-11-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Ocular Physiology, Regional Blood Flow

Keywords

eNOS Gene Polymorphism, ocular blood flow

Brief summary

Nitric oxide (NO) is a potent endothelium-derived vasodilatator that plays a major role in the control of ocular blood flow. Endothelial NO synthase (eNOS) is one of three isoforms of NOS producing NO through hydroxylation of L-arginine. The eNOS gene is located on the long arm of chromosome 7, and different polymorphic variations have been identified. These single nucleotide polymorphisms (sNP´s) have the ability to change transcription activity and therefore enzyme levels. Recent data indicate that the T -786C polymorphism (especially the homozygous variant) is associated with reduced eNOS activity and consequently impaired NO production. In the present study the investigators want to investigate if the T -786C eNOS gene polymorphism determines choroidal and optic nerve head blood flow.

Interventions

DRUGNG-monomethyl-L-arginine

intravenous administration, bolus over 5 minutes, dosage 6mg/kg

Study design

Allocation

NON_RANDOMIZED

Intervention model

PARALLEL

Primary purpose

DIAGNOSTIC

Masking

SINGLE (Investigator)

Eligibility

Sex/Gender

MALE

Age

19 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

* Men aged between 19 and 35 years, nonsmokers * Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant * Homozygous variants of the T -786C genotyping (CC or TT) * Normal ophthalmic findings, ametropia less than 3 diopters

Exclusion criteria

* Regular use of medication, abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study * Treatment in the previous 3 weeks with any drug * Symptoms of a clinically relevant illness in the 3 weeks before the first study day * History of hypersensitivity to the trial drug or to drugs with a similar chemical structure * History or presence of gastrointestinal, liver or kidney disease, or other conditions known to interfere with, distribution, metabolism or excretion of study drugs * Blood donation during the previous 3 weeks

Design outcomes

Primary

Measure	Time frame
Genotyping	performed during the first year before measurements

Countries

Austria

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026