Linked Life Data

16914127

Source:http://linkedlifedata.com/resource/pubmed/id/16914127

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2006-9-25
pubmed:abstractText
Glutathione transferase (GST) is a phase II detoxifying enzyme that plays a protective mechanism against oxidizing substances and toxic contaminants. Among these contaminants, heavy metals and polycyclic and halogenated aromatic hydrocarbons (PHAHs) have been shown to exert their toxic effects through the modulation of detoxifying enzymes, including the GSTs. Recently, we showed that heavy metals particularly Hg2+, Pb2+, and Cu2+ modulate the expression of phase II detoxifying enzymes such as NAD(P)H:quinone oxidoreductase 1 and Gsta1 in a concentration- and time-dependent manner. However, the effect of heavy metals and their potential interactions with aryl hydrocarbon receptor (AhR) ligands, PHAHs, on total Gst activity is still unknown. In the current study, we have investigated the effects of Hg2+, Pb2+, and Cu2+ in the absence and presence of four AhR ligands on the total Gst activity and reactive oxygen species (ROS) production in wild-type and AhR-deficient Hepa 1c1c7 cells. Our results showed that Hg2+ and Cu2+, but not Pb2+, significantly induced Gst activity in wild-type cells, whereas all metals induced the Gst activity in AhR-deficient cells. The induction of Gst activity by heavy metals was strongly correlated with an increase in the ROS production in wild-type, but not in AhR-deficient cells. Co-administration of heavy metals with AhR ligands differentially modulated Gst activity, in that co-exposure to Hg2+ plus AhR ligands could be beneficial in protecting against cytotoxicity as demonstrated by the increase in Gst activity with a proportional decrease in ROS production. Whereas co-exposure to Cu2+ plus AhR ligands was more toxic in that a decrease in Gst activity and an increase in oxidative stress of the cell were observed. We concluded that heavy metals differentially modulate the Gst activity through oxidative stress- and AhR-mediated mechanisms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0009-2797
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
162
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
237-48
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
The role of aryl hydrocarbon receptor and the reactive oxygen species in the modulation of glutathione transferase by heavy metals in murine hepatoma cell lines.
pubmed:affiliation
Faculty of Pharmacy and Pharmaceutical Sciences, 3126 Dentistry/Pharmacy Centre, University of Alberta, Edmonton, Alta., Canada T6G 2N8.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't