Preliminary researches have shown that reinfusion of ozonated blood may induce vasodilation in ischemic areas and reduce hypoxia. On the other hand ozone is associated with increased cardiovascular events and short-term inhalation of ozone at concentrations that occur in the urban environment causes acute conduit artery vasoconstriction. To help explain the mechanism behind these observations, we investigated the dose-dependent effect of ozonated solution on vascular function of central artery and microcirculatory system.