Reduced severity and neutrophil recruitment in peritonitis in females. (A-C and F) Male and female mice were treated with GBS (30 × 10⁶ bacteria per mouse IP; n = 7 mice) for 3 hours. (A) Total cell number recovered from the peritoneal cavity, (B) sepsis severity score, and (C) whole-blood bacterial count. (D) Phorbol myristate acetate (1 pg/mL)–induced NADPH oxidase activity in male and female resident peritoneal macrophages (10⁵ cells/sample), measured in vitro by Amplex Red for 7 minutes (n = 3 mice). (E) GBS levels after incubation in vitro (10⁴ bacteria/sample) for 1 hour at 37°C with normal mouse plasma (n = 3 samples from 6 mice in each group). (F) Concentration of GBS-induced cytokines in cell-free peritoneal lavage (n = 7 mice). (G-H) Male and female mice were injected with zymosan A (1 mg IP). (G) Total peritoneal cell number (n = 5-10; 2 independent experiments) and (H) number of F4/80⁺ macrophages, CD3⁺ T lymphocytes, CD19⁺ B lymphocytes, and GR1⁺ granulocytes in peritoneal cavity of male and female mice 3 hours after injection of zymosan A (n = 6 mice). All values (A-H) are expressed as means ± SEM. All comparisons are relative to male. *P < .05; **P < .01; and ***P < .001 by Student t test; §P < .05 by 2-way ANOVA followed by Bonferroni posttest; #P < .001.