A rabbit corneal epithelial cell line expresses functional platelet-derived growth factor beta-type receptors.

Platelet-derived growth factor (PDGF) is a family of three isoforms termed PDGF-AA, PDGF-AB, or PDGF-BB that induce proliferation in various mesenchymal cells. A rabbit corneal epithelial cell line (SIRC) was chosen to study the effects of the three isoforms of PDGF. These cells express approximately 43,000 PDGF beta-type receptors and less than 2800 alpha-type receptors on their surface. Thus, only PDGF-BB and -AB led to a transient dose-dependent rise in cytosolic free calcium with an effective dose for 50% of cells of 5 ng/ml. The PDGF-induced calcium signal is largely independent of the presence of extracellular calcium.