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

Medical University of Vienna

Status and phase: Terminated; Early Phase 1

Conditions: Regional Blood Flow; Ocular Physiology

Treatments: Drug: NG-monomethyl-L-arginine

Study type: Interventional

Funder types: Other

Identifiers

NCT00708357

OPHT-311004

Details and patient eligibility

About

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.

Enrollment: 12 patients

Sex: Male

Ages: 19+ years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Diagnostic

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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12 participants in 2 patient groups

1

Other group

Description:

homozygous mutant: CC allele of the eNOS T-786C gene

Treatment:

Drug: NG-monomethyl-L-arginine

2

Other group

Description:

homozygous mutant: TT allele of the eNOS T-786C gene

Treatment:

Drug: NG-monomethyl-L-arginine