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Dopaminergic Modulation of Choroidal Blood Flow Changes During Dark/Light Transitions

NCT00280501 · Status: COMPLETED · Phase: NA · Type: INTERVENTIONAL · Enrollment: 21

Last updated 2008-07-09

No results posted yet for this study

Summary

There is evidence from a variety of animal studies that choroidal blood flow is under neural control. By contrast, only little information is available from human studies. Recent results indicate that a light/dark transition is associated with a reduction in choroidal blood flow due to an unknown mechanism. We have shown that during unilateral dark/light transitions both eyes react with choroidal vasoconstriction strongly indicating a neural mechanism responsible for the blood flow changes.

Dopamine has been discussed as a chemical messenger for light adaptation. However, dopaminergic effects in the eye are not restricted to synaptic sites of release, but dopamine also diffuses to the outer retinal layers and pigment epithelium. Accordingly, dopaminergic effects also include a modulatory role on retinal vessel diameter and animal studies provide evidence for vasodilatory effects in the choroid. There is evidence that during darkness retinal and choroidal dopamine levels decrease. Accordingly, dopamine could provide a modulatory input to the light/dark transition induced changes of choroidal circulation. The aim of the present study is to test this hypothesis.

Conditions

  • Regional Blood Flow
  • Ocular Physiology

Interventions

DRUG

Quetiapine (drug)

Quetiapine (Seroquel 100mg-film-coated tablet, AstraZeneca Vienna, Austria) Dose: 100 mg tablet oral single dose

DRUG

Sulpiride (drug)

Sulpiride (Dogmatil 200mg-tablet, Synthélabo Groupe, Le Plessis Robinson, France) Dose: one half of 200 mg tablet oral single dose

DRUG

Placebo

Placebo

Sponsors & Collaborators

  • Medical University of Vienna

    lead OTHER

Principal Investigators

  • Gabriele Fuchsjaeger-Mayrl, MD · Department of Clinical Pharmacology

Study Design

Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Model
CROSSOVER

Eligibility

Min Age
18 Years
Max Age
35 Years
Sex
MALE
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2005-08-31
Primary Completion
2006-08-31
Completion
2006-08-31

Countries

  • Austria

Study Locations

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Entities

Drugs

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT00280501 on ClinicalTrials.gov