Fig. 5. Effect of toxin B and PLC inhibition on keratinocyte spreading. (A-F) Intracellular calcium release in primary human keratinocytes loaded with FURA-2. The x axis shows time in seconds and the y axis the level of fluorescence in arbitrary units. Keratinocytes in suspension were stimulated with 10 µM bradykinin (Brad) or 100 ng ml^-1 IGF-1 (IGF-1) without preincubation (A,B) or after preincubation with 1 µM (C) or 5 µM (E) U73122, or 1 µM (D) or 5 µM (F) U73343. (G-I) Histograms show size distribution of 200 keratinocytes per sample. Cells represented by black bars were pretreated with the following inhibitors: (G) 20 ng ml^-1 toxin B overnight; (H) 3 µM U73122 for 20 minutes; (I) 3 µM U73343 for 20 minutes. Grey bars show cells pretreated for the same time with the relevant vehicle control. All cells were plated in the presence of 100 ng ml^-1 IGF-1.