AMI: To clarify whether OX-LDL and simvastatin can induce the changes of PKC activity and cytosolic free Ca 2+ in rat aortic smooth muscle cells (ASMC). METHODS: PKC activity and cytosolic free Ca 2+ were measured by its ability to transfer phosphate from ATP to lysine-rich histone and flow cytometric analysis after loading with the Ca 2+ dye fluo 3/Am, respectively. RESULTS: OX-LDL increased PKC total activity in a dose-dependent manner and induced translocation of PKC from the cytosolic to membrane, while OX-LDL induced biphasic [Ca 2+ ]i responses including the rapid initial transient phase and the sustained phase. When simvastatin was added, the translocation of PKC was markedly decreased and simvastatin did not impair the initial peak response to OX-LDL but significantly reduced the subsequent plateau phase. CONCLUSSION: OX-LDL can induce dynamic changes of signal transduction of PKC and cytosolic free Ca 2+ in ASMC and these two events are closely linked.

AIM: To investigate effects of OX-LDL and VitE on the levels of IL-6,IL-8 and TNF-? in human umbilical vein endothelial cells(HUVEC). METHODS: Human umbilical vein endothelial cells were obtained by in vitro culture. HUVEC treated with or without Vit E was incubated with OX-LDL, and the levels of IL-6, IL-8 and TNF-? were determined by enzyme-linked immunosorbent assy technique. RESULTS:50 ?g/L,100 ?g/L, 200 ?g/L OX-LDL induced the release of IL-6,IL-8 and TNF-? by HUVEC in a dose-dependent manner. Compared with the control group , the levels of IL-6 and IL-8 were significantly increased at 6-12 h of stimulation with OX-LDL . Maximal levels of IL-6 and IL-8 occurred after 24-36 h, reaching a plateau maintained for at least 48 h. TNF-? rose after 2-6 h in HUVEC, and reached a maximum after 12 h. In contrast to IL-6 and IL-8, TNF-? declined after 48 h. However, when VitE (50 mg/L,100 mg/L,200 mg/L)was added, it can significant inhibited the release of IL-6, IL-8 and TNF-? in a dose-dependent manner, and after 48 h these cytokines have no diference between OX-LDL+VitE groups and OX-LDL groups. CONCLUSION: OX-LDL can obviously stimulate the production of IL-6,IL-8 and TNF-? in vascular endothelial cells, which can significantly be inhibited by VitE in a short time.