The effects of toxin A on colonic histopathology and protection against these effects by sulfasalazine and 5-ASA but not sulfapyridine. H&E-stained sections of rat colonic segments after they were treated intraluminally for 3 h with vehicle (a), 5 μg of toxin A (b), 5 μg of toxin A after chronic treatment with 100 mg/kg·day of sulfasalazine for 5 days (c), 5 μg of toxin A after acute pretreatment with 100 μg of 5-ASA for 30 minutes (d), and 5 μg of toxin A after acute pretreatment with 100 μg of sulfapyridine for 30 minutes (e). Scale bar, 100 μm.
