Objective To investigate the effect of arsenic trioxide on human coronary smooth muscle cells(HCSMCs). Method After the subculture of HCASMCs, cells were divided into 4 groups: control group and three arsenic trioxide (4.0 μmol/L) groups as the arsenic agent co-cultured with cells for 12,24 and 48 h. Flow cytometry and TUNEL were used for counting the ntmnber of cell apoptosis. RT-PCR was used to detect the expression of E2F-1 mRNA and Western blot was used to measure the levels of Bcl-2 ond Bax. Results Arsenic trioxide inhibited the proliferation of HCASMCs. When arsenic trioxide was 4.0 μmol/L, the living cells were ( 8.44 ±0.10) × 105/mL,signifiantly than that of control group (16.44 ± 1.34) × 105/mL, P ＜ 0.05. This inhibition of proliferation cycle was produced by affecting S and G2-M phase, which did not appear in the control group. Apoptotic cells increased from 16.0% ± 3.1% to 38.7% ± 2.7% (P ＜ 0.05) detected by TUNEL. The arsenic agnet decreased the Bcl-2 level and increased Bax. The expression of E2F-1 mRNA was decreased in 4.0 μmol/L arsenic trioxide group. Conclusions Arsenic trioxide exerts the apoptotic effect on human coronary smooth muscle cells.

Objective To investigate the apoptotic effects of arsenic trioxide on E2F-1 and EMAP-Ⅱ of hu-man coronary artery smooth muscle cells (HCASMCs). Method HCASMCs proliferated after culturing cells.Cells were divided into 4 groups: control group and arsenic trioxide (4.0μmol/L) 12 h group, 24 h group and 48 h group. Flow cytometry was used for counting number of apoptotic cells, RT-PCR was used for detecting the ex-pression of E2F-1 mRNA and Western blot was employed to get the level of EMAP-Ⅱ. Results Arsenic trioxide inhibited the proliferation of HCASMCs (living cells in 4.0 μmol/L arsenic trioxide were (8.44±0.10)×10~5/mL vs. control (16.44±1.34)×10~5/m (P <0.05), and the 4.0μmol/L arsenic trioxide inhibited proliferation cy-cle via affecting S and G2M phases, while those were not found in control group. E2F-1 mRNA expression was de-creased in 4.0 μmol/L arsenic trioxide group. Western blot test showed EMAP- Ⅱ level was also decreased in 4.0 μmol/L arsenic trioxide group. Conclusions Arsenic trioxide has apoptotic effect on smooth muscle cells of hu-man coronary artery and decrease the expression of E2F-1 mRNA and the level of EMAP- Ⅱ.