Composition and organization of the extracellular matrix of vein walls: collagen networks.

As there are few recent reports concerning the structure and exact composition of the extracellular matrix from human normal and varicose veins, we carried out comparative immunohistochemical analysis of vessel wall using conventional and confocal laser scanning immunofluorescence techniques. The present report is a rapid review of the structure and function of the 19 known collagen types and our first results on the distribution of collagen types VI, XII and XIV and laminin (glycoprotein from basement membrane) in vein walls. Type VI collagen is concentrated in the sub-endothelium and widely distributed in the media and adventice. For the first time, we demonstrated that both FACIT (fibril-associated) collagens XII and XIV were present in the vein wall, but at different anatomic sites.