FIG. 4.

FICZ-mediated AhR activation is prolonged through micro-osmotic pump implantation. Female C57BL/6 mice were treated with vehicle (VEH) or TCDD as described in Figure 1 or surgically implanted with subcutaneous micro-osmotic pumps loaded with either vehicle control (45% HPβCD) or FICZ released at a concentration of 10 μg/kg body weight/h. Mice were infected as described in Figure 1, 1 day after implantation or gavage. On the indicated days postinfection, RNA was isolated from lung and qRT-PCR was performed on RNA isolated from lungs of (A) mice implanted with FICZ-loaded (FICZ PUMP) and vehicle-loaded (VEH PUMP) micro-osmotic pumps and (B) TCDD and vehicle-treated mice. The mean fold change (± SEM) in Cyp1a1 was determined using the 2^−ΔΔCT method with L13 as the control gene (n = 2–9 mice per treatment group per day). An * indicates a significant difference in fold change Cyp1a1 expression compared with the vehicle control mice sacrificed on the same day of infection (p ≤ .05). Abbreviations: AhR, aryl hydrocarbon receptor; FICZ, 6-formylindolo[3,2-b]carbazole; HPβCD, hydroxypropyl-β-cyclodextrin; qRT-PCR, quantitative reverse transcription-PCR; TCDD, 2,3,7,8 tetrachlorodibenzo-p-dioxin.