Retinal Pigment Epithelial Cells in Culture Produce Retinal Vascular Mitogens

Abstract
• Conditioned medium from human retinal pigment epithelial cells in culture significantly stimulated the proliferation of subcultured bovine retinal capillary endothelial cells, pericytes, and freshly isolated retinal microvessels. The vascular mitogenic activity enhanced that of retinal crude extract. No evidence emerged of an inhibitor of microvascular cellular proliferation produced by retinal pigment epithelial cells.