Plasminogen activator release at the neuronal growth cone.

The site of plasminogen activator release by differentiated neuroblastoma clonal cell lines was determined with a fibrin overlay assay. Release of plasminogen activator was seen at the growth cone in 72 percent of the cells bearing neurites. For 21 percent of these cells the growth cone was the predominant or exclusive site of this enzyme activity. Selective release of protease at the "trailblazing" tip of the neurite may be important in neuron migration and neurite growth in vivo.