Properties and regulation of ion channels in MDCK cells

Abstract

The MDCK cell has proven to be a useful model cell line for the study of properties and regulation of renal epithelial ion channels. Patch clamp studies disclosed the existance of several K+ channels and of a Cl- channel, and their regulation by hormones, cell volume, trace elements and drugs. Most hormones affect K+ channels at least in part by increasing cytosolic Ca2+. However, indirect evidence points to additional mechanisms contributing to K+ channel activation. Cell swelling activates both K+ channels and unselective anion channels. I(Cln), a protein cloned from MDCK is either a Cl- channel or a regulator of thereof. I(Cln) is up-regulated by cellular acidification and is crucial for rapid regulatory cell volume decrease.