動脈硬化-組織培養によるアプローチ培養平滑筋細胞の増殖に及ぼすフィブリン, フィブリノーゲンおよびそれらの分解産物の影響

Abstract

Smooth muscle cells in the 7th-15th subculture from the media of the thoracic aorta of rabbits formed a characteristic pattern of “hills and valleys”, showing multilayered or monolayered arrangement. Ultrastructurally, their cytoplasm contained numerous bundles of myofilaments.Growth behavior of the cultured smooth muscle cells in response to fibrin clot was observed with phase-contrast microscope. Fibrin clot stimulated the proliferation of smooth muscle cells. Effects of fibrin, fibrinogen and FDP-D on the incorporation of [3H] thymidine by smooth muscle cells were studied in replicate culture method. Within 24 hours, both fibrin and fibrinogen stimulated the incorporation of [3H] thymidine, but, after 48 hours, inhibited the incorporation. FDP-D also inhibited the incorporation of [3H] thymidine by cultured smooth muscle cells.The cultured smooth muscle cells showed fibrinolytic activity both by cultivation on the fibrin film and by Todd's fibrinolysis autography.These results suggest that both fibrin and fibrinogen stimulate the proliferation of the smooth muscle cells. But, the proliferation of the smooth muscle cells was inhibited after 48 hours cultivation, and this phenomenon might be induced by the fibrin(ogen) degradation products produced by the fibrinolytic activity of the smooth muscle cells.