An expanding number of studies suggest a therapeutic role for nitrate and nitrite, most notably in treatment and prevention of cardiovascular disease including ischemia-reperfusion (IR) injury and hypertension. The nutritional aspects of these cardioprotective effects are particularly intriguing since nitrate and nitrite are abundant in our everyday diet.

Whether increasing the circulating pool of nitric oxide and nitrite by dietary nitrate offers a novel mechanistic approach to regulate mobilization of circulating angiogenic cells and thus regenerative processes in cardiovascular medicine is not known. Thus, in the present study, we tested whether oral application of nitrate leads to an enhanced number of circulating angiogenic cells and whether this is associated with an improvement in endothelial function.

Administration of a single dose of nitrate intervention or water alone to healthy volunteers. Before and up to 4 hours (short-term)/6 days (long-term) after ingestion, marker of vascular function are measured in plasma and by using high-resolution ultrasound.

Measurements are taken before and up to 4 h after double blind cross-over per os administration of a single dose of nitrate intervention (150 ml tab water with 150 umol/kg sodium-nitrate) or water control (100 ml Chapelle mineral water) to healthy volunteers. Circulating angiogenic cells are measured as CD34+/KDR+ and CD133+/KDR+ mononuclear cells in blood by flow cytometry and plasma is analyzed for nitrate and nitrite, as well as mobilization markers and cytokines including stromal cell derived factor, vascular endothelial growth factor and stem cell factor. All measurements are performed after >12h overnight fasting.

Inclusion Criteria:

• age > 20 years
• refrain from nitrate containing food ingestion during trial

Exclusion Criteria:

• > 36 years
• poor endothelial function
• acute infection
• any chronic heart or pulmonary disease
• arrhythmias
• acute or chronic renal failure
• cardio-vascular risk factors: diabetes mellitus, hypertension, hyperlipidemia
• intake of nutrition supplements (l-arginine, creatinine)