Figure 3. Pore formation primes PMNs for fMLF-stimulated production of O₂⁻.

(A) Formation of plasma membrane pores by electropermeabilization of human PMNs. PMNs were electropermeabilized (pulsed PMNs), as described in Materials and Methods, and plasma membrane permeability was evaluated using an EtBr uptake assay. Results are the mean ± se of three separate experiments. *P = 0.0006 for the comparison with PMNs that were not electropermeabilized (control PMNs) using a paired t test. (B) Forward light-scatter-height (FCS-H) and side light-scatter-height (SSC-H) in PMNs incubated with 1 nM PVL for 30 min or PMNs that have been electropermeabilized. (C) Electropermeabilization primes PMNs for enhanced fMLF-mediated production of O₂⁻. PMNs were electropermeabilized or incubated with 1 nM PVL for 30 min and then activated ± 1 μM fMLF for 20 min. Results are the mean ± se of three separate experiments. *P < 0.05 for the indicated comparisons using a one-way ANOVA and Tukey's post-test.