title: Triclosan, an environmental pollutant from health care products, evokes charybdotoxin-sensitive hyperpolarization in rat thymocytes.
abstract: The effects of triclosan, an environmental pollutant from household items and health care products, on membrane potential and intracellular Ca(2+) concentrations of rat thymocytes were examined by a flow cytometry with fluorescent probes, di-BA-C(4) and fluo-3-AM, because triclosan is often found in humans and wild animals. Triclosan at a concentration of 3 μM decreased the intensity of di-BA-C(4) fluorescence, indicating the triclosan-induced hyperpolarization. The application of charybdotoxin, a specific inhibitor of Ca(2+)-dependent K(+) channels, and the removal of external Ca(2+) eliminated the triclosan-attenuation of di-BA-C(4) fluorescence. Furthermore, triclosan augmented the fluo-3 fluorescence under normal Ca(2+) condition, indicating that triclosan increased intracellular Ca(2+) concentration. These results suggest that triclosan induces membrane hyperpolarization by increasing intracellular Ca(2+) concentration that activates Ca(2+)-dependent K(+) channels. Since the change in membrane potential of lymphocytes influence cellular immune functions, triclosan may exert adverse actions on immune system in human and wild animals.
authors: Laboratory of Cellular Signaling, Faculty of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770-8502, Japan. t.kawanai@gmail.com
authors: Takuya
authors: T
authors: Kawanai
mesh_terms: D000814:Aniline Compounds; D000818:Animals; D001463:Barbiturates; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects*; D016764:Cell Polarity / Q000187:drug effects; D018999:Charybdotoxin / Q000494:pharmacology*; D004785:Environmental Pollutants / Q000009:adverse effects*; D005434:Flow Cytometry; D005453:Fluorescence; D005456:Fluorescent Dyes; D007555:Isoxazoles; D008564:Membrane Potentials / Q000187:drug effects; D026902:Potassium Channel Blockers / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D060168:Thymocytes / Q000187:drug effects* / Q000378:metabolism; D014260:Triclosan / Q000009:adverse effects*; D014966:Xanthenes
chemical_list: D000814:Aniline Compounds; D001463:Barbiturates; D004785:Environmental Pollutants; D005456:Fluorescent Dyes; D007555:Isoxazoles; D026902:Potassium Channel Blockers; D014966:Xanthenes; C052795:bis(1,3-dibutylbarbiturate)trimethine oxonol; D018999:Charybdotoxin; C059715:Fluo-3; D014260:Triclosan; D002118:Calcium