Physiological roles of chloride ions in bodily and cellular functions.

Physiological roles of Cl^-, a major anion in the body, are not well known compared with those of cations. This review article introduces: (1) roles of Cl^- in bodily and cellular functions; (2) the range of cytosolic Cl^- concentration ([Cl^-]_c); (3) whether [Cl^-]_c could change with cell volume change under an isosmotic condition; (4) whether [Cl^-]_c could change under conditions where multiple Cl^- transporters and channels contribute to Cl^- influx and efflux in an isosmotic state; (5) whether the change in [Cl^-]_c could be large enough to act as signals; (6) effects of Cl^- on cytoskeletal tubulin polymerization through inhibition of GTPase activity and tubulin polymerization-dependent biological activity; (7) roles of cytosolic Cl^- in cell proliferation; (8) Cl^--regulatory mechanisms of ciliary motility; (9) roles of Cl^- in sweet/umami taste receptors; (10) Cl^--regulatory mechanisms of with-no-lysine kinase (WNK); (11) roles of Cl^- in regulation of epithelial Na⁺ transport; (12) relationship between roles of Cl^- and H⁺ in body functions.