Investigation of the metabolism of L-fucose in aortic tissue and cultured arterial wall cells.

tions in the pattern o f newly synthesized and secreted proteins. There appeared t o be three main modulations under the influence of the fucopolysaccharide. One occurred o n SDS/PAGE in the area o f low molecular mass proteins (below 46 kDa) and two alterations occurred in the area of high molecular mass proteins of 220 kDa and 180 kDa. These two proteins were identified as fibronectin and thrombospondin. lmmunoprecipitation and quantification revealed that the synthesis of fibronectin is reduced under the influence of fucoidan, whereas thrombospondin synthesis was increased (Fig. 1). The effect of fibronectin was not shared by heparin. Moreover, it could bc shown that desulphation of native fucoidan abolished the observed modulation o n fibronectin and thrombospondin. The effect o f fucoidan on the synthesis of the two extracellular matrix proteins is an early time event after addition of the fucopolysaccharide t o growth-stimulated smooth muscle cells. This argues for a connection between the observed influence o n cell proliferation and the modulation of the composition o f the extracellular matrix o f smooth muscle cells. The observed differences in the modulation of extracellular matrix proteins by fucoidan compared with heparin suggest different pathways of the action o f both sulphatcd polysaccharides on smooth muscle cells.