The demonstration of angiogenic activity from ocular tissues. Preliminary report.

Human, bovine, and rabbit retinal extracts are shown to be capable of stimulating (1) proliferation and thymidine uptake of bovine vascular endothelial cells in cultures and (2) neovascularization of the chick chorioallantoic membrane (CAM). Extracts of skeletal muscle, heart, and liver lack similar stimulatory activity. Vitreous aspirates from patients with proliferative diabetic retinopathy, in a preliminary study, were able to stimulate vascular endothelial cell thymidine uptake. Most vitreous samples from patients without intraocular neovascularization lacked similar stimulatory activity. Indirect evidence suggests the liberation of an angiogenic factor from the retina in several ocular disorders. The data contained in this report represent the first direct evidence of angiogenic activity from mammalian retina.