Figure 2.

Absence of Stx3, but not Stx4, influences the amount, rate, and size of vesicles exocytosed in MCs. Shown are C_m recordings of individual peritoneal MCs after stimulation by intracellular dialysis of GTPγS and Ca²⁺. Access to the cell interior was obtained via establishment of the whole-cell recording configuration at time 0. Sham, +/+ MCs dialyzed with a solution lacking GTPγS. The color key in A applies to all panels. A and E, representative traces of C_m recordings. B and F, ΔC_m after stimulation. Numbers inside boxes in B and F, number of cells studied, obtained from 6–8 animals of each genotype; applies to D, H, and I–L. C and G, representative normalized C_m traces. D and H, rate of exocytosis between 40 and 60% of total ΔC_m. I and J, time between cell access and beginning of the exocytic burst. K and L, frequency distribution of C_m step sizes between 1 and 15% of total ΔC_m. Signals < 4 fF have been removed for clarity. White line, mean; box, 25th–75th percentile; whiskers, 5th–95th percentile. #, p ≤ 0.05; †, p ≤ 0.01; *, p ≤ 0.001; all compared with +/+ MCs unless otherwise specified.