Effects of toxin A on colonic luminal fluid accumulation, MPO activity, and histopathology and inhibition of these effects by TRPV1 antagonism. (a) Toxin A-induced stimulation of colonic luminal fluid accumulation and the inhibition of this effect by pretreatment with 1 μg of I-RTX administered intraluminally 30 min before toxin A. (b) Toxin A-induced stimulation of colonic MPO activity and the inhibition of this effect by pretreatment with 1 μg of I-RTX administered intraluminally 30 min before toxin A. H&E-stained sections of rat colonic segments after they were treated intraluminally for 3 h with vehicle (c), 1 μg of I-RTX (d), 5 μg of toxin A (e), or 5 μg of toxin A after pretreatment with 1 μg of I-RTX 30 min before toxin A administration (f). Scale bar, 100 μm. * versus toxin A(−)/I-RTX(−); ** versus toxin A(−)/I-RTX(−); # versus toxin A(+)/I-RTX(−).
