Fig. 4. Effects of ionomycin on DCs: [Ca²⁺]_i increase and surface area expansion. Panel A shows the increase of the fura-2 ratiometric [Ca²⁺]_i signal in a DC suspension exposed to IONO (arrow). The average increases at 1 minute (results of four experiments ± s.d.) in DCs, non-pretreated (NPT) and pretreated with Wort, Vac1 or BAPTA-AM, are shown in B. Panel C shows the prompt IONO-induced (arrow) increase of FM1-43 fluorescence recorded in a DC suspension analyzed in the presence of the dye, documenting cell surface expansion; panel D shows the average 1 minute FM1-43 fluorescence increases in DC suspensions pretreated as in panel B (results of four experiments ± s.d.).