RT Book, Section A1 Böger, Rainer H. A2 Dieter, Robert S. A2 Dieter, Raymond A. A2 Dieter, Raymond A. SR Print(0) ID 1127164565 T1 The Endothelium in Health and Disease T2 Peripheral Arterial Disease YR 2009 FD 2009 PB McGraw-Hill Education PP New York, NY SN 9780071481793 LK accesscardiology.mhmedical.com/content.aspx?aid=1127164565 RD 2023/03/28 AB Each and every blood vessel throughout the body is covered, at its inner, luminal surface, by a monolayer of specialized cells, i.e., the vascular endothelial cells. This monolayer represents the primary anatomical site that separates the compartment of the flowing blood from the body's interstitium. Although spread throughout the body and thus not easily discernible, all endothelial cells together cover a surface that has been estimated as 350 m2 (see Ref. 1) and may count as many as 60 trillion (6 × 1013) cells.2 The total weight of all endothelial cells has been estimated to be between 110 g3 and 750 g, or as much as the liver.4 Recent scientific evidence has made clear that the endothelium may not be less metabolically active than the liver. It was 25 years ago when the ground-breaking experimental studies discovered the crucial role of the endothelium in regulating vascular smooth muscle tone and coagulation and it was concluded that the endothelium is not merely a passive barrier.5,6,7