Fig. 3. SEM of IgG-E phagocytosis in macrophages treated with the drugs. (A) A phagocytic cup in a control macrophage after 7-minute incubation with IgG-Es. The phagocytic cup is conformed closely to the surface of IgG-Es. The cylindrical cup appeared to have constricted the IgG-Es. After 30 minutes, IgG-Es were no longer seen on the cell surface, because all had been internalized by the cells (not shown). (B) In wortmannin-treated macrophages, many phagocytic cups were observed on the dorsal surface of macrophages. The configuration of phagocytic cups was similar to that in control cells at 7 minutes after phagocytosis. (C) ML-7 treatment also did not inhibit phagocytic-cup formation. Most strikingly, phagocytic cups were not closely apposed to the surfaces of IgG-Es. (D) Cytochalasin D inhibited phagocytic-cup formation. IgG-Es bound to the plane dorsal surface of the cells. Electron micrographs were pseudocolored using Adobe Photoshop. Bars, 5 µm.