RESUMO
AIM: To investigate the influences of native and oxidized lipoprotein(a) on human arterial smooth muscle cell (SMC) proliferation, change of intracellular free calcium concentration ([Ca 2+ ] i) and the protective effect of sodium ferulate(SF). METHODS: Lp(a) was oxidized by Cu 2+ and the extent of oxidation was assessed by the MDA content.Human SMC were incubated in culture media with SF for 12 h, then exposed to Lp(a) and oxidized-Lp(a), respectively. MTT colorimetry and flow cytometry were used to evaluated the proliferation of SMC and flurorescent indicator Fura-2/AM was used to determined [Ca 2+ ] i. RESULTS: ox-Lp(a) significantly promoted proliferation of SMC and increased[Ca 2+ ] i compared with Lp(a). SF(40,80 mg/L) remarkedly inhibited SMC proliferation and decreased the rising of [Ca 2+ ] i induced by ox-Lp(a) in a dose-dependent manner, but no effect on SMC proliferation and the increase in [Ca 2+ ] i induced by Lp(a).CONCLUSION: ox-Lp(a) induces the strong growth-promoting effect in SMC through increasing in [Ca 2+ ] i, which might be one of the cellular mechanisms responsible for the higher atherogenic potential of ox-Lp(a) compared with Lp(a), and this process can be prevented by inhibiting of oxidation by SF.