Effect of Irbesartan on Endothelial Function of the Retinal Vasculature in Patients With Hypercholesterolemia

Inclusion Criteria: * Male patients aged 18-65 years with LDL-cholesterol \>= 130mg/dl * Male healthy control subjects aged 18-65 years Exclusion Criteria: * All kinds of secondary hyperlipidemia. * Advanced damage of vital organs (grades III and IV retinopathy) * Lipid-lowering drugs (including lipid lowering dietary supplements or food additives) within the last 4 weeks * History of serious hypersensitivity reaction to AT1-receptor blockers * Actual or anamnestic alcohol- or drug abuse. * Smokers or ex-smokers \< 1 year. * Patients with Diabetes mellitus (oral medication or insulin). * Patients with arterial fibrillation or AV-Block (II° or more). * Patients with anamnestic myocardial infarction. * Patients with instable angina pectoris including EcG-aberrations or cardiac insufficiency NYHA III or IV. * History of malignancy (unless a documented disease-free period exceeding 10 years is present) with the exception of basal cell carcinoma of the skin * History of allograft transplantation * Patients with anaphylaxis or known therapy resistance of the used test matters * Therapy with not approved concomitant medication, or participation in a clinical study within 4 weeks preceding treatment start. * Disease which interfere with the pharmacodynamics and pharmacokinetics of the study drug. * Liver or kidney disease with SGOT, GPT, g-GT, AP, bilirubin and creatinin above 200% of standard. * Patients, who are not sufficiently compliant, or patients, who are not capable or willing to appear for controlling visits. * Presumed risk of transmission of HIV or hepatitis via blood from the proband