Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-8-17
pubmed:abstractText
To evaluate health effects of chemical mixtures, such as multiple heavy metals in drinking water, we have been developing efficient and accurate hazard identification strategies. Thus, in this study, we determine the cytotoxicity of arsenic, cadmium, chromium, and lead, and characterize interactions among these metals in human epidermal keratinocytes. Three immortal keratinocyte cell lines (RHEK-1, HaCaT, and NM1) and primary keratinocytes (NHEK) were used. A statistical approach applying an additivity response surface methodology was used to test the validity of the additivity concept for a 4-metal mixture. Responses of the 4 keratinocyte strains to the metal mixture were highly dose-dependent. A growth stimulatory effect (hormesis) was observed in RHEK-1, NM1, and NHEK cells with the metal mixture at low concentrations (low ppb range). This hormesis effect was not significant in HaCaT. As the mixture concentration increased, a trend of additivity changed to synergistic cytotoxicity in all 4 cell strains. However, in NHEK, RHEK-1, and HaCaT, at the highest mixture concentrations tested, the responses to the metal mixtures were antagonistic. In NM1, no significant antagonistic interaction among the metals was observed. To explore a mechanistic basis for these differential sensitivities, levels of glutathione and metallothioneins I and II were determined in the keratinocyte cell strains. Initial data are consistent with the suggestion that synergistic cytotoxicity turned to antagonistic effects because at highest mixture exposure concentrations cellular defense mechanisms were enhanced.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1096-6080
pubmed:author
pubmed:issnType
Print
pubmed:volume
63
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
132-42
pubmed:dateRevised
2010-9-17
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Toxicological interactions among arsenic, cadmium, chromium, and lead in human keratinocytes.
pubmed:affiliation
Quantitative and Computational Toxicology Group, Center for Environmental Toxicology and Technology, Department of Environmental Health, Colorado State University, Fort Collins, Colorado 80523, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.