Objective    To evaluate the potential protective effects of erythropoietin (EPO) in combination with granulocyte-colony stimulating factor (G-CSF) on hypoxia cardiomyocytes.     Meth

ods    After left ventricular cardiomyocytes were isolated from neonate rat

the cells were inoculated in a cultural atmosphere of 95%N

2

and 5%CO

2

for 24 h to establish hypoxia cardiomyocytes model. The protective effects of EPO and G-CSF at different concentrations were evaluated for the optimal concentration. Then the protective effects of EPO in combination with G-CSF were investigated under the optimized concentrations. The survival

apoptotic and necrotic rates of cardiomyocytes were assessed by flow cytometry.     Results    The mortality and  ratio of apoptotic cells to total necrotic cell were higher in hypoxia cardiomyocytes than normal cells significantly (26.73% vs 5.63%，70.05% vs 37.83%

P0.01). At the condition of 1 U/ml EPO and 6 ng/ml G-CSF

protective effect was observed

When the concentrations of EPO was 5

25

and 125 U/ml

similar outcome was seen. G-CSF of 150 ng/ml showed the most effective

and 30 and 750 ng/ml were similar. The apoptotic rate and total necrotic rate of hypoxia cardialmyocytes were significantly lower in EPO(5 U/ml)

G-CSF (30ng/ml) and combination groups than in the hypoxia group [(18.73±1.08)%

(8.01±2.28)%

(7.08±0.16)% vs (4.57±0.99)%，P0.01

(26.73±1.30)%

(11.88±3.69)%

(11.6±0.65)% vs (8.15±3.16)%，P0.01). The protective effects of EPO and G-CSF were similar (P0.05)

and the combination group was much better than EPO and G-CSF alone groups (P0.01).     Conclusion     EPO and G-CSF exert protective effect on hypoxia cardiomyocytes

and the optimized concentration for EPO is 5 U/ml and for G-CSF is 30 ng/ml. The protective effects of EPO in combination with G-CSF on hypoxia cardiomyocytes are better than EPO or G-CSF alone.