Figure 2. Histology of ileal-cecal intestinal tissue sections.

(A–D), H&E staining; (A'–D'), alcial blue staining. (A, A') mice, implanted with placebo pellet. (B, B') mice, implanted with morphine pellet. (C, C') mice, implanted with placebo pellet and intestinal inoculation with P. aeruginosa PAO1, 200 μl of 10⁷ CFU/ml via direct puncture. Increased amount of goblet cells in crypts is shown by arrow. (D, D') mice, implanted with morphine pellet and injected P. aeruginosa PAO1 similar to C. Focal superficial necrosis (shown by black arrows on panel D, C') and the appearance of lymophocytic infiltration (shown by yellow arrows) are seen. Images were taken with Zeiss Axioskop using a 20 × objective. (E), Quantitative assessment of intestinal mucus abundance represented by % of blue stained mucus/field using ACIS software (Automated Cellular Imaging Software) n=40 fields of evaluation from 4 mice/group, *p<0.05 Placebo vs morphine; **p<0.05 Placebo vs Placebo + P. aeruginosa; ***p<0.001 Placebo vs morphine + P. aeruginosa). (F, G), Production of (F) IL-6 and (G) IL-10 in serum and cecum. (H) QRT-PCR to detect P. aeruginosa PAO1 in cecal lumen, intestinal epithelium, and blood of mice 36 hours following P. aeruginosa inoculation into the cecum. •, mouse 1; ∘, mouse 2; ▾, mouse 3; and Δ, mouse 4.