Effects of cobalt chloride on phenotypes of normal human saphenous vein smooth muscle cells.

To explore the cellular adaptations and responses to hypoxia in normal human saphenous vein smooth muscle cells (SMCs) and presume what roles phenotypic modulation of normal human saphenous vein SMCs would play in varicose vein of lower extremity, we used cobalt chloride (CoCl2), a hypoxia mimetic, to treat normal human saphenous vein SMCs in vitro. The proliferating ability of cells exposed to serial dilutions of CoCl2 (0, 200, 300, 400 and 500 μM) at 24 h, 48 h and 72 h respectively was detected by MTT assay. Wound healing assay was used to observe the migrating ability of cells under CoCl2 (200 μM) treatment for 8 days continuously. Hoechst 33258 stain was used to determine whether hypoxia induced by CoCl2 could cause apoptosis of normal human saphenous vein SMCs. We found that CoCl2 enhanced the proliferation and inhibited the migration of normal human saphenous vein SMCs. The apparent morphous of normal human saphenous vein SMCs under chronic CoCl2 treatment was significantly changed compared to no CoCl2 treated control, but this process did not relate to cell apoptosis. To conclude, our results support the concept that the phenotypes of normal human saphenous vein SMCs could be influenced by hypoxia stimulus. Cellular structural and functional changes under chronic hypoxia in normal human saphenous vein SMCs might play important roles in the development of varicose veins of lower extremity.