ABSTRACT
Vascular endothelium is one of the large organs of the human body with a number of cells on the order of 1013; the total weight of endothelial cells in a 70 kg man is several hundred grams. These cells are arranged as the inner surface of all blood vessels, and thus the total surface area of endothelium which is in contact with blood is on the order of several thousand square meters under resting conditions; this area can be increased several fold in response to increased demand for blood fl ow in certain tissues (e.g., during strenuous exercise) by means of capillary recruitment (Wolinsky 1980).
