Changes of peroxide dismutase activity and malondialdehyde level in the smooth muscle cells of human fetal aorta cultured in vitro by low density lipoprotein conditional medium

Here are reported the changes of superoxide dismutase(SOD)activity andmalondialdehyde(MDA)in the smooth muscle cells of human fetal aorta cultured in vitro with lowdensity lipoprotein(LDL)conditional medium.The results showed that a single concentration of hu-man LDL(50μg/ml)stimulated proliferation of smooth muscle cells,and the SOD activityof the cells in the experimental group was higher,from the first to the fifth cultured day whenthe cells had a active proliferation,than that of the control cells.This suggests that LDL might in-duce the increase of SOD activity.At the seventh day,as the cells were in inactive proliferation,SOD activity was low and the difference was significant as compared with that at the fifth day ofthe same group.This also indicates that the SOD activity may be related to the cell proliferation.MDA level within the cells of the esperimental group was lowered with the cell active proliferationand the increase of SOD activity,but when the cells were in inactive proliferation and the SOD ac-tivity decreased,it will remained low.