Effect of the flavonol quercetin on membrane conductances in rat colonic crypt cells.

The plant polyphenol quercetin was shown to induce Cl- secretion in rat colon. This study was performed to investigate the alterations of membrane conductances in isolated epithelial cells induced by quercetin. Whole-cell patch-clamp recordings were performed in isolated crypts from rat distal colon. In cells of the crypt basis, quercetin significantly hyperpolarized the membrane potential at concentrations > or =3 microM and increased the K+ conductance without visibly altering the Cl- conductance. Thus, quercetin induces Cl- secretion merely by activation of K+ channels in the colon epithelium.