Effect of Antioxidants on Ocular Blood Flow, Endothelial Function, and Cytokine Levels in LPS Induced Inflammatory Model in Humans.

Summary

Oxidative stress, which refers to cellular damage caused by reactive oxygen intermediates, has been implicated in many disease processes, especially age-related disorders. Many trials investigating use of antioxidants in protecting different tissues against oxidative stress have been conducted, but the results are ambiguous.

Inflammation is generally associated with enhanced oxidative stress and widespread endothelial dysfunction. In the present study, the infusion of LPS, which is a cell wall component of Gram-negative bacteria and a major mediator in the pathogenesis of septic shock, will be used as a standardized experimental model of systemic inflammatory response in humans. The assessment of outcome parameters will include measurements of ocular blood flow, forearm blood flow and plasma concentration of cytokines. Measurements of ocular hemodynamics provide an unique chance to investigate local blood flow in humans non-invasively. Moreover, the retina is especially susceptible to oxidative stress because of its high consumption of oxygen, its high polyunsaturated fatty acid content, and its exposure to visible light. Evidence from literature clearly supports a role for oxidative stress in pathophysiology of several ocular diseases including diabetic retinopathy and age-related macular degeneration. To investigate the retinal vascular reactivity we will use systemic hyperoxia as a stimulus. The measurement of forearm blood flow will be use to assess endothelial function. The main study objective is to investigate the effect of oral vitamins and minerals supplementation on impaired retinal vascular reactivity after LPS administration.

Conditions

• Retina
• Regional Blood Flow
• Endotoxin, Escherichia Coli

Interventions

DRUG

vitamin and mineral supplement

dose: 4 tablets daily for two weeks vitamin A 7160 IU, vitamin C 113mg, vitamin E 100IU, zinc 17.4mg, copper 0.4mg

DRUG

Escherichia coli Endotoxin (LPS)

dose: 2 ng/kg (corresponding to 20 IU/kg), intravenous bolus over 5 minutes on both study days

DRUG

100% O2

breathing for 30 minutes, 2 breathing periods on both study days

DRUG

nitroglycerin

dose: 0,8 mg sublingual, applied during FMD measurements on both study days

Sponsors & Collaborators

• Medical University of Vienna

  lead OTHER

Principal Investigators

• Michael Wolzt, MD · Department of Clinical Pharmacology, Medical University of Vienna

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

35 Years

Sex

MALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2006-09-30

Primary Completion

2007-12-31

Completion

2007-12-31

Countries

• Austria

Study Locations