Over-expression of human protein kinase C-α in murine NIH 3T3 fibroblasts is associated with an increased platelet-derived growth factor- and phorbol ester-mediated formation of prostaglandins, whereas the calcium ionophore-induced release of arachidonic acid metabolites is unaffected; however, the differences of arachidonic acid and prostaglandin formation are much more pronounced with platelet-derived growth factor than with phorbol ester. Platelet-derived growth factor induces an identical elevation of intracellular free calcium in control and protein kinase C-α over-expressing cells; the phorbol ester has no effect on intracellular free calcium in both cell lines. These results demonstrate that protein kinase C-α may couple to arachidonic acid cascade in NIH 3T3 fibroblasts.
