Granulocyte-macrophage colony stimulating factor improves cardiac function in rabbits following myocardial infarction

Objective: To investigate the therapeutic potency of recombinant human Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) in a rabbit myocardial infarction model. Methods: A myocardial infarction was created by the ligation of the major ventricular branch of the left coronary artery in rabbits. After myocardial infarction, the animals were randomly assigned to GM-CSF treatment group, untreated groups and sham-operated group. The rabbits of the treated group were injected into GM-CSF by subcutaneous administration, 10 μg/kg/day, once a day for 5 days. The untreated and sham-operated group received a equal saline in the same manner as treated group. Six weeks later echocardiography and haemodynamic assessment were undertaken to assesse cardiac function. The size of the infarct region of the heart were also studied. Results: The untreated group exhibited significant higher left ventricle end-diastolic pressure, higher central venous pressure, and with significant lower mean blood pressure, lower peak first derivative of left ventricle pressure (dP/dt) than the sham group. Also, Rabbits in untreated group display significant systolic dysfunction shown by the decreased ejection fraction, diastolic dysfunction shown by increasing in the ratio of E wave to A wave (E/A), and display left ventricle enlargement. However, GS-CSF singnificantly prevented heart dysfunction, left ventricle enlargement, and reduced infarct size in treatment group. Conclusion: Administration GM-CSF after cardiac infarction can improve heart function. These findings indicate the technique may be a novel and simple therapeutic method for ischemic myocardium.