Fig. 5. (A) Mast cells were permeabilised with SL-O in the presence of 100 µM MgATP, 10 µM GTPS and 3 mM Ca:EGTA at pCa 5 for 3 minutes at 30°C as in Fig. 4A, in the presence of 10 µM U73-122 or U73-343, 3 mM neomycin, 40 µM Et-18-OMe, 100 µM LY294002, 100 µM LY303511 or 5 mM ß-GP. (B) Cells were permeabilised in the presence of 300 µM Ca:EGTA at pCa 8; after two minutes, the indicated peptide was added to 100 µM. After a further 5 minutes at 30°C, Ca:EGTA at pCa 5 and GTPS were added to the same final concentrations as (A), and the cells incubated for 5 minutes. Cells were then fixed and stained with 2C11 (red) and Alexa Fluor 647-concanavalin A (blue). Top panels show merged images of 2C11 and concanavalin A; bottom panels show the fluorescence intensity profile for 2C11. Bar, 10 µm.