EFFECT OF PLATELET-ACTIVATING-FACTOR ON CELL-DIFFERENTIATION OF TRYPANOSOMA-CRUZI

The effects of platelet-activating factor (PAF), at 10(-6)M and 10(-9) M, on cell growth and cell differentiation of Trypanosoma cruzi were i nvestigated. Cell differentiation was evaluated by both light and elec tron microscopy. At the concentrations used, PAF slightly interfered w ith the protozoan growth. However, parasites growth in the presence of PAF were significantly more differentiated than those grown in the ab sence of PAF, beginning on the fourth day of culture. A specific PAF r eceptor antagonist (WEB 2086) totally abrogated PAF effect on cell dif ferentiation. These findings indicate that PAF triggers the process of cell differentiation in T. cruzi and suggest that these parasites hav e receptors for PAF. (C) 1996 Academic Press, Inc.