Effects of 5-ASA on capsaicin-induced colonic luminal fluid accumulation and MPO activity. 5-ASA was administered intraluminally at a dose of 100 μg for 30 minutes before capsaicin. (a) Capsaicin stimulation of colonic luminal fluid accumulation and the lack of significant inhibition of this effect by acute pretreatment with 5-ASA. (b) Capsaicin stimulation of colonic MPO activity and the lack of significant inhibition of this effect by acute pretreatment with 5-ASA. H&E-stained sections of rat colonic segments after they were treated intraluminally for 3 h with vehicle (c), 100 μg of 5-ASA (d), 4 mg of capsaicin (e), or 4 mg of capsaicin after pretreatment with 100 μg of 5-ASA 30 min before toxin A administration (f). Scale bar, 100 μm. * versus sulfapyridine-/toxin A-.
