[A basic study on omental transplantation. Vascular endothelial cell growth factor in human omentum]

Omentum tissue has potent angiogenic activity, so transplantation is often effective in treatment of moyamoya disease. Omentum was homogenized and fractionated to investigate the presence of an endothelial cell growth factor. The effectiveness of extracts was measured by the growth activity of bovine aortic endothelial cell incubated for 6 days with various omentum extracts. The lipid fraction had no growth promoting activity. However, the water soluble extracts were active. The activity could be increased by ammonium sulfate precipitation (60-80% saturation). Gel permeation chromatography of the ammonium sulfate fraction showed that the endothelial growth factor had an apparent molecular weight of 96,000. Heparin affinity chromatography revealed poor heparin affinity. The activity was stable at pH 3.5 and pH 9.5, but inactivated by heating at 70 degrees C for 10 minutes or 100 degrees C for 2 minutes. These properties clearly distinguish the omentum-derived growth factor (OmDGF) from the heparin binding growth factor. OmDGF is probably distinct from other vascular endothelial cell growth factors.