Criteria for the Molecular Identification of the Volume-Sensitive Outwardly Rectifying Cl⁻ Channel : Letter to the Editor

Anion channels are activated by volume expansion in most animal cell types and are known to be implicated not only in regulatory volume decrease but also in many other cell activities that are associated with changes in cell volume and shape, including cell proliferation and cell death (Okada, 1998). Among a variety of swelling-activated Cl⁻ channels (I_Cl.swell), the most important and frequently observed channel is a volume-sensitive, outwardly rectifying, ATP-dependent Cl⁻ channel (Okada, 1997; termed VSOR-ClC here). The functional properties of VSOR-ClC have so far been intensively and systematically studied in rat C6 glioma cells (Strange et al., 1996), human epithelial Intestine 407 cells (Okada, 1997), and human and bovine endothelial cells (Nilius et al., 1997), and proved to share the same properties. The principal phenotypic properties are attributed to the pore and regulatory characteristics,...