[PDGF-induced calcium increase in cultivated epithelial cells in the cattle lens]

Platelet-derived growth factor (PDGF) is one of numerous growth factors regulating development of the ocular lens and its component parts. Although little is known about its site of action on the cell and the mechanisms of this confirmed mitogenic action, a close connection has been assumed between the influence of PDGF on both the lens epithelium and intracellular calcium homeostasis. The present study therefore examined the influence of PDGF on the concentration of intracellular free calcium [( Ca2+]i) in primary cultivated bovine epithelial cells. A dose-dependent [Ca2+]i increase of up to 300% followed stimulation with PDGF (5-50 ng/ml) in a medium containing Ca2+. [Ca2+]i also rose significantly in Ca(2+)-free medium, indicating mobilization from intracellular storage.