title: Effect of bisphenol A on Ca(2+) fluxes and viability in Madin-Darby canine renal tubular cells.
abstract: The effect of the environmental contaminant, bisphenol A, on cytosolic free Ca(2+) concentrations ([Ca(2+)](i)) in Madin-Darby canine kidney (MDCK) cells is unclear. This study explored whether bisphenol A changed basal [Ca(2+)](i) levels in suspended MDCK cells by using fura-2 as a Ca(2+)-sensitive fluorescent dye. Bisphenol A, at concentrations between 50 and 300 µM, increased [Ca(2+)](i) in a concentration-dependent manner. The Ca(2+) signal was reduced, partly, by removing extracellular Ca(2+). Bisphenol A induced Mn(2+) influx, leading to quenching of fura-2 fluorescence, suggesting Ca(2+) influx. This Ca(2+) influx was inhibited by phospholipase A2 inhibitor aristolochic acid, store-operated Ca(2+) channel blockers nifedipine and SK&F96365, and protein kinase C inhibitor GF109203X. In Ca(2+)-free medium, pretreatment with the mitochondrial uncoupler, carbonylcyanide m-chlorophenylhydrazone (CCCP), and the endoplasmic reticulum Ca(2+) pump inhibitors, thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ), inhibited bisphenol A-induced Ca(2+) release. Conversely, pretreatment with bisphenol A abolished thapsigargin (or BHQ)- and CCCP-induced [Ca(2+)](i) rise. Inhibition of phospholipase C with U73122 abolished bisphenol-induced [Ca(2+)](i) rise. Bisphenol A caused a concentration-dependent decrease in cell viability via apoptosis in a Ca(2+)-independent manner. Collectively, in MDCK cells, bisphenol A induced [Ca(2+)](i) rises by causing phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and mitochondria and Ca(2+) influx via phospholipase A2-, protein kinase C-sensitive, store-operated Ca(2+) channels.
authors.affiliation: Department of Nursing, Tzu Hui Institute of Technology, Pingtung, Taiwan.
authors.forename: Chun-Chi
authors.initials: CC
authors.lastname: Kuo
authors.forename: Jong-Khing
authors.initials: JK
authors.lastname: Huang
authors.forename: Chiang-Ting
authors.initials: CT
authors.lastname: Chou
authors.forename: Jin-Shiung
authors.initials: JS
authors.lastname: Cheng
authors.forename: Jeng-Yu
authors.initials: JY
authors.lastname: Tsai
authors.forename: Yi-Chien
authors.initials: YC
authors.lastname: Fang
authors.forename: Shu-Shong
authors.initials: SS
authors.lastname: Hsu
authors.forename: Wei-Chuan
authors.initials: WC
authors.lastname: Liao
authors.forename: Hong-Tai
authors.initials: HT
authors.lastname: Chang
authors.forename: Chin-Man
authors.initials: CM
authors.lastname: Ho
authors.forename: Chung-Ren
authors.initials: CR
authors.lastname: Jan
mesh_terms: D000818:Animals; D001559:Benzhydryl Compounds; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects*; D018929:Cell Culture Techniques; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003627:Data Interpretation, Statistical; D004171:Diploidy; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D052244:Endocrine Disruptors / Q000633:toxicity*; D005434:Flow Cytometry; D007684:Kidney Tubules / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D010636:Phenols / Q000633:toxicity*; D064801:Phospholipase A2 Inhibitors; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D002118:Calcium; D052244:Endocrine Disruptors; D010636:Phenols; D064801:Phospholipase A2 Inhibitors; D010738:Type C Phospholipases; C006780:bisphenol A; D000098826:Bisphenol A Compounds