Intraluminal Administration of Resiniferatoxin Protects against Clostridium difficile Toxin A-Induced Colitis

Figure 2

Dose-response effects of intraluminal RTX on ileal histopathology assessed by H&E staining. RTX had a biphasic effect on histopathology that matched the biphasic effects on luminal fluid accumulation and MPO activity seen in Figure 1. At low doses (0.01–0.1 μg), RTX dose dependently caused increasing inflammation as assessed by loss of villi, loss of normal crypt architecture, and infiltration of immune cells into the lamina propria (panels (b) and (c)). However, at higher doses (1–100 μg), RTX had no effect (panels (d)–(f)). (a) Vehicle control (no RTX); (b) 0.01 μg RTX; (c) 0.1 μg RTX; (d) 1.0 μg RTX; (e) 10 μg RTX; and (f) 100 μg RTX. Scale bar = 100 μm.

(a)

(b)

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(f)