Male and female mice (C57BL/6; 10 weeks old) were gonadectomized. One week later, control or hormone pellets were implanted (E2: 0.006 mg/pellet, DHT: 5 mg/pellet). One week after pellet implantation, mice were exposed to either FA or O3 (2 ppm, 3h), and intratracheally infected with K. pneumoniae (450 CFU/mouse). Survival was monitored for 14 days.