Table 2.

Major functions of pulmonary endothelium

	Function
1.	Barrier function52-55
2.	Regulation of coagulation and thrombolysis56,57
3.	Drug removal and biotransformation58-61
4.	Active interactions with cellular components of blood, with bacteria, viruses, or any particulate compounds found in the blood or in the tissue62-65
5.	Expression of a variety of receptors and signaling molecules66-70
6.	Expression of definite enzymes such as NO synthase, ACE, endothelin converting enzyme, lipoprotein lipase71-73
7.	Synthesis of vasoactive autacoids involved in establishing and controlling the vascular tone as well as the blood flow74-76
8.	Binding and interacting with immune complexes and immunocompetent cells upon activation77-79
9.	Production of ROS and RNS, cytokines, growth factors80-83
10.	Expression of adhesion molecules84-87
11.	Expression of specific structural elements (fenestrations, diaphragms, interendothelial sealing, supramolecular complexes)88-90

^NoteACE: angiotensin-converting enzyme; RNS: reactive nitrogen species; ROS: reactive oxygen species.