The effects of mucus on the binding of cationized ferritin by human and animal gastrointestinal epithelium.

Human gallbladder and gastric epithelial cells are normally covered with a layer of mucus. When specimens were exposed to cationized ferritin (CF) in vitro, they did not regularly bind nor internalise it. If the tissues were first exposed to the mucolytic agents cysteamine or pepsin, then the gallbladder epithelium readily bound CF and the gastric epithelium irregularly. The in vivo binding of CF by guinea pig gallbladder could be abolished by the induction of mucous hypersecretion by the antibiotic lincomycin. The removal of the mucus by mucolytic agents restored the binding of CF. The irregular binding of CF by gastric mucosa after the use of mucolytic agents suggests other factors may be at play.