Non-heparin-binding endothelial cell growth factor from bovine omentum

The graft of omental pedicle is known to be clinically effective for wound healing and revascularization of ischemic organs. We found that bovine greater omentum contained growth factor that was capable of stimulating the proliferation of bovine aortic endothelial cells. Gel filtration of the tissue extract showed at least two activity peaks corresponding to molecular weights of 96,000 and 21,000. The major Mr 21,000 growth factor was partially purified approx 120-fold from the omental extract. The purified factor was not mitogenic to BALB/c 3T3 cells and, importantly, had no affinity for immobilized heparin. This factor is thus clearly distinct from fibroblast growth factors and related mitogens. The pI of the factor was estimated to be 5.6-6.0. This factor may be involved in the potent angiogenic activity expressed by the implanted omentum. The omental fat, which was previously shown to cause neovascularization in the assay in vivo, did not promote the growth of endothelial cells in vitro.