Effects of hydrogen peroxide on cell proliferation and expression of gelatinase A and its inhibitor in vascular smooth muscle cells

AIM: To study the effects of hydrogen peroxied (H 2O 2) on cell proliferation and transcription of gelatinase A (MMP-2) and its inhibitor (TIMP-2) in vascular smooth muscle cells (VSMC). METHODS: Cell proliferation and toxicity by H 2O 2 were tested through MTT. The expression of MMP-2 mRNA and TIMP-2 mRNA in VSMC were evaluated by RT-PCR. RESULTS: The present study showed that H 2O 2 (more than 300 μmol/L)was lethal to VSMC. 0 01-50 μmol/L H 2O 2 promoted proliferation of VSMC in a time-dependant manner. A value (optical density) was reached to peak at 24 h after continuing stimulation of 10 μmol/L H 2O 2. MMP-2/β-actin mRNA ratio significantly increased after stimulation with 1 μmol/L?10 μmol/L H 2O 2. TIMP-2/β-actin mRNA ratio was not significantly fluctuated at 12 h?24 h?36 h?48 h after continuing stimulation with 1 μmol/L, 10 μmol/L, and 50 μmol/L H 2O 2.CONCLUSION: H 2O 2 at suitable concentrations stimulated proliferation of VSMC and induced transcription of MMP-2 gene in VSMC. There was no effect of H 2O 2 on transcription of TIMP-2 gene in VSMC. These results imply that H 2O 2 takes part in the pathological course of vascular remodeling through VSMC.