[Effect of granulocyte-macrophage colony stimulating factor on the function and regeneration of myocardium in rats...

To test the reparative capacity of stromal cells in myocardial infarction, rats were injected with granulocyte-monocyte-colony stimulating factor (GM-CSF) (leukomax), a cytokine known by its ability to raise a level of stromal cells in the blood, during first three days after coronary artery ligation. Only 10 of 17 rats (59%) survived 4 weeks in this group compared with 16 of 24 (67%) among rats not treated with leukomax. Echocardiographic and electromanometric studies showed that in both groups ventricular (LV) dilatation which developed during first hours after surgery persisted throughout 6-8 weeks and was combined with decreased ejection fraction and elevated LV end diastolic pressure. These alterations correlated with infarct size which varied from 0 to 28% of left ventricular weight in both groups. There were no statistically significant differences in functional and morphometric measurements between groups receiving and not receiving GM-CSF. However this result may be inconclusive due to small number of investigated animals and broad variation of ischemic zone size in each group.