Neutralization of the fibrogenic silica-released macrophage factor by antiserum

Antiserum against the fibrogenic factor from the culture medium of silica-treated rat macrophages was produced in rabbits. In dilution 1: 10,000 the antiserum cancelled the stimulating effect of the culture medium of rat macrophages on the 3H-proline incorporation into granulation-tissue fibroblasts. The rabbit antiserum had variable effects on the stimulation by the media of silica-treated human monocytes, but no effect on the media of cultured human SU-DHL-2-cells.