Figure 4.

(a) Synthesis of PAF by EC in response to the insertion of MAC (C5_b-9) at sublytic concentrations for various periods of time (shaded columns). As negative control, EC were subsequently incubated in the presence of the C5_b-like C5C6 complex (C5C6*) and C7, then of C8, but not C9, for various periods of time (open columns). As positive control, EC were incubated with PLN (1 U/ml for 15 min) or thrombin (THR) (2 U/ml for 5 min) in the absence of serum. PAF was expressed as ng of PAF associated with 2·5 × 10⁶ cells. Data are from a representative experiment, with triplicate points. anova with Newman–Keul's multicomparison test was performed (*P < 0·05 versus control). (b) Synthesis of PAF by PMN in response to the insertion of MAC (C5_b-9) at sublytic concentrations for various periods of time (shaded columns). As negative control, PMN were subsequently incubated in the presence of the C5_b-like C5C6 complex (C5C6*) and C7, then of C8, but not C9, for various periods of time (open columns). As positive control, PMN were stimulated with C3_b-coated Baker's yeast particles (BYS) for 20 min in the absence of serum. PAF was expressed as ng of PAF associated with 2·5 × 10⁶ cells. Data are from a representative experiment, with triplicate points. anova with Newman–Keul's multicomparison test was performed (*P < 0·05 versus control).