Decreased colonic mucus in rats with loperamide-induced constipation

Constipation is a risk factor of colorectal cancer. Mucin is a major compon ent of lumenal mucus, which protects the colorectal mucosa against mechanic al and chemical damage. The aim of this study was to evaluate mucus product ion and to quantitate lumen mucus in a rat model of spastic constipation. W e induced constipation with loperamide (1.5 mg/kg), and histochemically eva luated mucus production and the thickness of the mucus layer at the fecal s urface. We quantitated the mucus attached to the mucosal surface using colo nies perfusion with N-acetylcysteine, While more feces remained in the colo n, there was less fecal excretion and lower fecal water content in loperami de-administered rats than in control rats. Crypt epithelial cells contained less mucus in constipated rats than in control rats. The mucus layer at th e fecal surface was thinner and less mucus was recovered from the mucosal s urface in constipated rats than in control rats. Mucus production of crypt epithelial cells and mucus at the fecal and mucosal surface were reduced by loperamide-induced constipation. (C) 2000 Elsevier Science Inc. All rights reserved.