Abstract: Objective To preliminarily explore the effects of 1,2-dichloroethane and chloroacetic acid on the cell cycle and apoptosis in rat glioma cells and rat Schwann cells. Methods 0,15,30,60 mmol/L 1,2-dichloroethane and 0,225,450,900 μmol/L chloroacetic acid were co-cultured with rat glioma cells and rat Schwann cells for 24 h,respectively. The changes in the cell cycle and apoptosis were detected by flow cytometry,to evaluate the toxicity of 1,2-dichloroethane and chloroacetic acid in the two cells. Results With the increasing toxic doses of 1,2-dichloroethane and chloroacetic acid,the relative cell survival rate was gradually decreased in both cells. The IC₅₀ value of 1,2-dichloroethane was （77.1±1.4） and （72.9±4.3）mmol/L in rat glioma cells and rat Schwann cells respectively. The IC₅₀ value of chloroacetic acid was （895.0±44.5） and （803.2±37.3）μmol/L in rat glioma cells and rat Schwann cells respectively. The apoptosis rates of 0,15,30,60 mmol/L 1,2-dichloroethane in rat glioma cells were respectively （5.55±0.78）%,（4.93±0.08）%,（6.31±0.53）% and（38.93±2.53）%,the cell ratios in G₀/G₁ phase were respectively （61.46±0.79）%,（62.43±2.13）%,（60.19±6.41）% and（43.39±4.82）%,in S phase were respectively（13.46±4.57）%,（16.89±3.25）%,（18.56±4.68）% and（32.23±3.49）%,in G₂/M phase were respectively（23.36±4.53）%,（18.58±5.57）%,（20.14±6.40）% and（23.12±6.46）%. 1,2-dichloroethane can cause an increased rate of apoptosis,lower cell ratio in G0/G1 phase and increased cell ratio in S phase in rat glioma cells at the dose of 60 mmol/L（all P<0.01）. The apoptosis rates of 0,15,30,60 mmol/L 1,2-dichloroethane in rat Schwann cells were respectively （5.50±1.89）%,（7.95±2.38）%,（7.89±0.99）% and （29.20±7.53）%,and the cell ratios in G₀/G₁ phase were respectively （39.08±3.20）%,（44.00±20.65）%,（42.15±18.03）% and（37.65±6.39）%,in S phase were respectively（28.15±3.62）%,（25.77±15.47）%,（25.20±7.58）% and（23.85±2.00）%,in G₂/M phase were respectively （32.02±2.78）%,（29.58±7.06）%,（31.49±12.27）% and（37.10±7.68）%. 60 mmol/L 1,2-dichloroethane can cause an increased rate of apoptosis in rat Schwann cells（P<0.01）. The apoptosis rates of 0,225,450,900 μmol/L chloroacetic acid in rat glioma cells were respectively （5.55±0.78）%,（6.87±4.07）%,（5.16±0.95）% and（5.70±1.21）%,and the cell ratios in G0/G1 phase were respectively （61.46±0.79）%,（60.15±7.92）%,（61.27±3.11）% and （63.57±3.51）%,in S phase were respectively （13.46±4.57）%,（18.81±5.95）%,（16.92±4.68）% and （13.99±1.34）%,in G₂/M phase were respectively （23.36±4.53）%,（18.93±1.96）%,（19.90±4.91）% and （20.86±2.03）%. The apoptosis rates of 0,225,450,900 μmol/L chloroacetic acid in rat Schwann cells were respectively（5.50±1.89）%,（7.60±2.60）%,（9.20±2.92）% and （37.88±6.99）%,and the cell ratios in G₀/G₁ phase were respectively（39.08±3.20）%,（39.88±6.06）%,（37.30±9.58）% and（36.59±7.16）%,in S phase were respectively（28.15±3.62）%,（20.91±7.76）%,（22.01±7.28）% and（16.72±5.49）%,in G₂/M phase were respectively （32.02±2.78）%,（38.54±2.71）%,（38.74±5.21）% and（45.49±5.70）%. 900 μmol/L chloroacetic acid can cause an increased rate of apoptosis and increased cell ratio in G₂/M phase in rat Schwann cells（both P<0.05）. Conclusion 1,2-dichloroethane can cause increased apoptotic rate of rat glioma cells and Schwann cells,cycle arrest in rat glioma cells. Chloroacetic acid can cause increased apoptotic rate and cycle arrest in rat Schwann cells.

Key words: 1,2-dichloroethane, Chloroacetic acid, Rat glioma cells, Rat Schwann cells, Cell cycle, Cell apoptosis