Estrogen receptor antagonist alters AHR in female mice. (A) Effect of daily administration of an estrogen antagonist on AHR in female mice. Open circles, 10 days saline/10 days vehicle; solid circles, 10 days OVA/10 days vehicle; open triangles, 10 days saline/10 days ICI (10 mg/kg/d); solid triangles, 10 days OVA/10 days ICI (10 mg/kg/d). (B) Effect of daily administration of the antagonist in male mice after 10-day OVA inhalation in vivo. Open squares, 10 days saline/10 days vehicle; solid squares, 10 days OVA/10 days vehicle; diamonds, 10 days OVA/10 days ICI (10 mg/kg/d). AHR was assayed 24 hours after the last OVA challenge. ICI182,780 at a dose of 10 mg/kg/d was administered intraperitoneally immediately before each OVA challenge. Results represent the mean ± SEM (n = 8). **P < 0.01 and ##P < 0.01 comparing 10-day saline/10-day vehicle and 10-day OVA/10-day vehicle.