Chemotaxis of rat brain astrocytes to platelet derived growth factor.

Using a purified population of rat brain astrocytes prepared from neonatal cortex, we investigated the chemotaxis of astroglia to several well characterized growth factors. Chemotactic activity for astrocytes was found for the platelet derived growth factor with a half maximal response occurring at 0.5 ng/ml as compared with a value of 2-3 ng/ml obtained for NIH/3T3 fibroblasts in control experiments. Other growth factors including epidermal growth factor, fibroblast growth factor and insulin were inactive as chemoattractants. Affinity purified fibronectin was also found to stimulate the migration of astroglia, with half maximal doses of approximately 1 microgram/ml relative to maximal responses to platelet derived growth factor.