Premium
Uncoupling effect of mercuric chloride on mitochondria isolated from an hepatic cell line
Author(s) -
Königsberg Mina,
LópezDíazguerrero Norma Edith,
Bucio Leticia,
GutiérrezRuiz María Concepción
Publication year - 2001
Publication title -
journal of applied toxicology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.784
H-Index - 87
eISSN - 1099-1263
pISSN - 0260-437X
DOI - 10.1002/jat.763
Subject(s) - mitochondrion , oligomycin , dithiothreitol , mercury (programming language) , cytosol , oxidative phosphorylation , bioenergetics , chemistry , biochemistry , respiration , oxidative stress , respiratory chain , antimycin a , cell , biophysics , biology , atpase , enzyme , anatomy , computer science , programming language
Abstract A human fetal hepatic cell line (WRL‐68) was used as a model to study the damage produced by mercury. The Hg(II) uptake by WRL‐68 cells was found to be in a biphasic manner with a rapid initial uptake phase lasting about 5 min, followed by a sustained phase of slower accumulation. Distribution of mercury was studied and mitochondria were found to be the major target for mercury in this cell line (48%), followed by nuclei (38%), cytosol (8%) and microsomes (7%). Mitochondrial morphological damage after mercury treatment was observed by transmission electron microscopy. To determine if the toxic effect of mercury on mitochondrial bioenergetics was direct or indirect, mitochondria were isolated from WRL‐68 cells after 1 h of pre‐incubation with 0.5 µM HgCl 2 . Oxygen consumption was quantified in two sets of experiments: in the presence of classical mitochondrial respiratory inhibitors; and in the presence of oligomycin. No significant difference was found in respiration with classical inhibitors, indicating that mercury does not affect directly the mitochondrial respiratory chain. However, mitochondria of Hg‐treated cells were not inhibited when oligomycin was added, probably due to an uncoupling effect. This effect was prevented with dithiothreitol (DTT) treatment. A possible explanation for mercury's effect on mitochondria and its relation with oxidative stress is presented. Copyright © 2001 John Wiley & Sons, Ltd.