血管内皮細胞表面ヘパリン様物質の意義

抄録

Incubation of porcine aortic endothelial cell cultures with β-D-xyloside resulted in a reduction of ¹²⁵I-antithrombin III binding to cells in parallel with the decrease in biosynthesis of radiolabeled heparan sulfate on the cell surface. Characterization of heparan sulfate revealed that neither a size nor a charge density of the molecule was altered by β-D-xyloside treatment. In the medium from xyloside-treated cultures, free chondroitin sulfate chains were markedly increased. On the other hand, incubation of endothelial cells with n-butyrate caused a significant increase in the amount of antithrombin bound to cells, while growth and morphological appearances of cells were influenced by this treatment. Incorporation of radiolabeled sulfate into glycosaminoglycans in the medium and cells from n-butyrate-treated cultures was not different from that in control. These results suggest that β-D-xyloside treatment of endothelial cells caused a dose-depandent decrease in production of cell surface heparan sulfate, which could serve as antithrombin binding sites on endothelial cells, and that n-butyrate treatment led to a qualitative rather than quantitative change in heparan sulfate, resulting in a increase in antithrombin binding to cells. Thus, altered synthesis of cell surface heparan sulfate could affect interactions of antithrombin III with endothelium.