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CompletedNCT00280501Updated Jul 9, 2008

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

An interventional study of Quetiapine (drug) and Sulpiride (drug) in Regional Blood Flow and Ocular Physiology, sponsored by Medical University of Vienna. Completed at 1 site in Austria. Open to male participants aged 18 Years to 35 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2008-07-09.

Sponsored by Medical University of Vienna · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
21
Allocation
Randomized
Ages
18 Years to 35 Years
Sex
Male
01

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.

02

Conditions studied

  • Regional Blood Flow
  • Ocular Physiology

Keywords

  • Sulpiride
  • Quetiapine
  • Light/dark transition
  • Choroidal blood flow
03

In context

Lead sponsor

Medical University of Vienna is the lead sponsor of 1,076 studies on the registry; 177 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 35 Years
Sexes eligible
Male
Accepts healthy volunteers
Yes

Inclusion criteria

  • Men aged between 18 and 35 years, nonsmokers
  • Body mass index between 15th and 85th percentile
  • Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
  • Normal laboratory values unless the investigator considers an abnormality to be clinically irrelevant
  • Normal ophthalmic findings, ametropia \< 3 Dpt.

Exclusion criteria

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
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Double (Participant, Investigator)
Enrollment
21 participants (actual)

Study arms

  • Active comparator
    1

    Quetiapine

    Drug: Quetiapine (drug) · Drug: Sulpiride (drug) · Drug: Placebo

  • Active comparator
    2

    Sulpiride

    Drug: Quetiapine (drug) · Drug: Sulpiride (drug) · Drug: Placebo

  • Placebo comparator
    3

    Placebo

    Drug: Quetiapine (drug) · Drug: Sulpiride (drug) · Drug: Placebo

Interventions

  • DrugQuetiapine (drug)

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

  • DrugSulpiride (drug)

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

  • DrugPlacebo

    Placebo

06

What researchers measure

Primary outcomes

  1. choroidal blood flow

    Time frame: in total 3x 3 hours

  2. fundus pulsation amplitude

    Time frame: in total 3 x 3 hours

07

Study locations

1 site
  • Department of Clinical Pharmacology
    Vienna, 1090, Austria
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 9, 2008, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT00280501
Lead sponsor
Medical University of Vienna
First posted
Jan 23, 2006
Start date
Aug 2005
Primary completion
Aug 2006
Completion
Aug 2006
Last update
Jul 9, 2008

Study contacts

Gabriele Fuchsjaeger-Mayrl, MD
principal investigator · Department of Clinical Pharmacology

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Jul 2008. You cannot join it, but the record below documents what was studied.

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