Unbalanced expression of VEGF and PEDF in ischemia-induced retinal neovascularization

Retinal levels of vascular endothelial growth factor (VEGF) and pigment epi thelium-derived factor (PEDF), an angiogenic inhibitor, mere measured and c orrelated with the ischemia-induced retinal neovascularization in rats, The retinas with neovascularization showed a 5-fold increase in VEGF while 2-f old decrease in PEDF, compared to the age-matched controls, resulting in an increased VEGF/PEDF ratio. The time course of the VEGF/PEDF ratio change c orrelated with the progression of retinal neovascularization. Changes in th e VEGF and PEDF mRNAs preceded their protein level changes. These results s uggest that an unbalance between angiogenic stimulators and inhibitors may contribute to retinal neovascularization. (C) 2001 Federation of European B iochemical Societies. Published by Elsevier Science B.V. All rights reserve d.