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Effects of dietary lectins on ion transport in epithelia
Author(s) -
Kunzelmann Karl,
Sun J,
Schreiber R,
König Jens
Publication year - 2004
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1038/sj.bjp.0705857
Subject(s) - phospholipase c , epithelial sodium channel , biology , ussing chamber , protein kinase c , cystic fibrosis , brush border , chemistry , biochemistry , medicine , endocrinology , secretion , sodium , receptor , kinase , membrane , organic chemistry , vesicle
Phytohemagglutinins are widely distributed in common food items. They constitute a heterogeneous group of proteins, which are often resistant to proteolysis in the gastrointestinal tract. Upon binding to the luminal membrane of intestinal cells, they can interfere with digestive, protective or secretory functions of the intestine. Phytohemagglutinins present in red kidney beans and jackbeans have been shown to induce diarrhea and hypersecretion in human airways, but the underlying mechanisms remain obscure. We examined how agglutinins from wheat germ (WGA), soy bean (SBA), red kidney beans (Pha‐E, Pha‐L), and jackbeans (Con‐A) affect ion transport in mouse airways and large intestine using Ussing chamber techniques. We found that Pha‐E, Pha‐L, and Con‐A but not WGA and SBA inhibit electrogenic Na + absorption dose dependently in both colon and trachea. The inhibitory effects of Con‐A on Na + absorption were suppressed by the sugar mannose, by inhibition of phospholipase C (PLC) and protein kinase C (PKC). Thus, nutritional phytohemagglutinins block salt absorption in a PLC‐ and PKC‐dependent manner, probably by inhibition of the epithelial Na + channel (ENaC). This effect may be therapeutically useful in patients suffering from cystic fibrosis.British Journal of Pharmacology (2004) 142 , 1219–1226. doi: 10.1038/sj.bjp.0705857