Premium
Ca 2+ mobilization induced by δ‐hexachlorocyclohexane in Madin Darby canine kidney cells
Author(s) -
Jan ChungRen,
Wang JueLone,
Lin MuhChiou,
Lee Kam Chung,
Chou KangJu,
Chiang HungTing
Publication year - 2000
Publication title -
drug development research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.582
H-Index - 60
eISSN - 1098-2299
pISSN - 0272-4391
DOI - 10.1002/1098-2299(200006)50:2<186::aid-ddr8>3.0.co;2-a
Subject(s) - cyclopiazonic acid , thapsigargin , endoplasmic reticulum , chemistry , fura 2 , calcium , intracellular , biophysics , phospholipase c , biochemistry , cytosol , biology , signal transduction , organic chemistry , enzyme
The effect of the pesticide δ‐hexachlorocyclohexane (δ‐HCH) were examined on Ca 2+ signaling in Madin Darby canine kidney (MDCK) using fura‐2 as a Ca 2+ probe. δ‐HCH at concentrations of 5–200 mM increased intracellular free Ca 2+ concentration ([Ca 2+ ] i ) concentration‐dependently. The [Ca 2+ ] i increase comprised an immediate rise followed by a sustained phase within 5 min of measurement. External Ca 2+ removal slightly reduced the [Ca 2+ ]i increase. In Ca 2+ ‐free medium, 150 μM δ‐HCH did not increase [Ca 2+ ] i after pretreatment with carbonylcyanide m‐chlorophenylhydrazone (CCCP; 2 μM), a mitochondrial uncoupler, and two endoplasmic reticulum (ER) Ca 2+ pump inhibitors, thapsigargin (1 μM) and cyclopiazonic acid (100 μM). Conversely, pretreatment with δ‐HCH prevented thapsigargin, cyclopiazonic acid, and CCCP from releasing more Ca 2+ , suggesting 150 μM δ‐HCH released Ca 2+ from the ER and mitochondria. δ‐HCH (150 μM) activated Mn 2+ quench of fura‐2 fluorescence, confirming that δ‐HCH induced Ca 2+ influx. Addition of 3 mM Ca 2+ induced a concentration‐dependent [Ca 2+ ] i increase after pretreatment with 100–200 μM δ‐HCH for 870 sec in Ca 2+ ‐free medium. The δ‐HCH (150 μM)‐induced Ca 2+ release was decreased by inhibiting phospholipase C with 1 μM U73122. Collectively, we have found that δ‐HCH increased [Ca 2+ ] i in MDCK cells by releasing Ca 2+ from the ER and mitochondria, followed by capacitative Ca 2+ entry. Drug Dev. Res. 50:186–192, 2000. © 2000 Wiley‐Liss, Inc.