Lack of Action of Serum Opsonins in Phagocytosis of Inert Particles by Cells of Reticuloendothelial System

Abstract

SummaryIncubation of carbon particles with normal sera originating from various animal species and with sera from R.E.S. stimulated mice does not affect the rate of carbon phagocytosis by R.E. cells. These findings show that serum opsonins do not act as a limiting factor in carbon phagocytosis. Depression of R.E.S. phagocytic function by “blockade”with colloidal carbon is due to a saturation of phagocytic cells rather than to a depletion of serum opsonins. These results confirm that the rate of carbon blood clearance is a reliable method for measuring phagocytic activity of R.E. cells.