Growth control in cerebral microvessel-derived endothelial cells.

Endothelial (En) cells derived from the cerebral microvasculature were examined for their growth control properties. These cells were shown to be growth responsive to fetal bovine serum and arrested growth if serum was removed. They lend themselves to studies in chemically defined media since they survive well in serum-free medium with little or no proliferation. These cerebral microvessel En cells also respond to epidermal growth factor (EGF) and platelet-derived growth factor (PDGF), unlike some other endothelial cells. Similar to other endothelial cells, the En cells responded to fibroblast growth factor (FGF). The response to EGF and PDGF occurred in serum-free media, but only if both agents were present. The cells further responded mitogenically to conditioned media obtained from transformed endothelial cells. The En cells were found to bind EGF and displayed two orders of affinity as determined by Scatchard analysis, depending upon whether the cells were in confluent or subconfluent conditions. The data indicate that some endothelial cells respond to EGF and PDGF and that one mechanism for growth control of endothelial cells may be an ability to regulate high-affinity growth factor receptors for epidermal growth factor.