Dopaminergic Modulation of Choroidal Blood Flow Changes During Dark/Light Transitions
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 21
- 试验地点
- 1
- 主要终点
- choroidal blood flow
研究概览
简要总结
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 18 Years 至 35 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •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.
排除标准
- •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
研究组 & 干预措施
1
Quetiapine
干预措施: Quetiapine (drug) (Drug)
1
Quetiapine
干预措施: Sulpiride (drug) (Drug)
1
Quetiapine
干预措施: Placebo (Drug)
2
Sulpiride
干预措施: Quetiapine (drug) (Drug)
2
Sulpiride
干预措施: Sulpiride (drug) (Drug)
2
Sulpiride
干预措施: Placebo (Drug)
3
Placebo
干预措施: Quetiapine (drug) (Drug)
3
Placebo
干预措施: Sulpiride (drug) (Drug)
3
Placebo
干预措施: Placebo (Drug)
结局指标
主要结局
choroidal blood flow
时间窗: in total 3x 3 hours
fundus pulsation amplitude
时间窗: in total 3 x 3 hours
次要结局
未报告次要终点