title: Ketoconazole-evoked [Ca2+]i rises and non-Ca2+-triggered cell death in rabbit corneal epithelial cells (SIRC).
abstract: The effect of ketoconazole on cytosolic free Ca2+ concentrations ([Ca2+]i) and proliferation has not been explored in corneal cells. This study examined whether ketoconazole alters Ca2+ levels and causes cell death in SIRC rabbit corneal epithelial cells. [Ca2+]i and cell viability were measured by using the fluorescent dyes fura-2 and WST-1, respectively. Ketoconazole at concentrations of 5 microM and above increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced partly by removing extracellular Ca2+. The ketoconazole-induced Ca2+ influx was insensitive to L-type Ca2+ channel blockers and protein kinase C modulators. In Ca2+-free medium, after pretreatment with 50 microM ketoconazole, thapsigargin-(1 microM)-induced [Ca2+]i rises were abolished; conversely, thapsigargin pretreatment nearly abolished ketoconazole-induced [Ca2+]i rises. Inhibition of phospholipase C with 2 microM U73122 did not change ketoconazole-induced [Ca2+]i rises. At concentrations between 5 and 100 microM, ketoconazole killed cells in a concentration-dependent manner. The cytotoxic effect of 50 microM ketoconazole was not reversed by prechelating cytosolic Ca2+ with BAPTA. In summary, in corneal cells, ketoconazole-induced [Ca2+]i rises by causing Ca2+ release from the endoplasmic reticulum and Ca2+ influx from unknown pathways. Furthermore, the cytotoxicity induced by ketoconazole was not caused via a preceding [Ca2+]i rise.
authors: Department of Ophthalmology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
authors: Muh-Chiou
authors: MC
authors: Lin
authors: Chorng-Chih
authors: CC
authors: Huang
authors: Chun-Jen
authors: CJ
authors: Huang
authors: He-Hsiung
authors: HH
authors: Cheng
authors: Chiang-Ting
authors: CT
authors: Chou
authors: Jue-Long
authors: JL
authors: Wang
authors: I-Shu
authors: IS
authors: Chen
authors: Shiuh-Inn
authors: SI
authors: Liu
authors: Yih-Chau
authors: YC
authors: Lu
authors: Hong-Tai
authors: HT
authors: Chang
authors: Jong-Khing
authors: JK
authors: Huang
authors: Jin-Shyr
authors: JS
authors: Chen
authors: Chung-Ren
authors: CR
authors: Jan
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology; D002118:Calcium / Q000737:chemistry / Q000378:metabolism*; D016923:Cell Death; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000378:metabolism; D007654:Ketoconazole / Q000494:pharmacology*; D008956:Models, Chemical; D011493:Protein Kinase C / Q000378:metabolism; D011817:Rabbits; D013997:Time Factors
chemical_list: D000935:Antifungal Agents; D011493:Protein Kinase C; D007654:Ketoconazole; D002118:Calcium