Linked Life Data

10079212

Source:http://linkedlifedata.com/resource/pubmed/id/10079212

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1999-4-15
pubmed:abstractText
Polychlorinated biphenyls (PCBs) are persistent environmental pollutants associated with spontaneous abortion and shortened gestation length in women and animals. In previous studies, we showed that PCB mixtures and noncoplanar ortho-substituted PCB congeners increased contractions in pregnant rat uterus. In the present study, we hypothesized that the PCB mixture Aroclor 1242 (A1242) stimulates oscillatory uterine contraction in pregnant uterus by increasing intracellular calcium concentration ([Ca2+]i). Pretreatment of uterine strips with ryanodine or thapsigargin, to deplete specific intracellular calcium stores, did not prevent the increased frequency of oscillatory contraction due to 50 microM A1242, whereas thapsigargin effectively blocked carbachol-induced stimulation of uterine contraction. However, 100 microM A1242 was unable to increase contraction in the absence of extracellular calcium or in the presence of the voltage-operated L-type calcium channel blocker nifedipine. A1242 (100 microM) was observed to partially depolarize the cell membrane of myometrial cells from pregnant rats, as measured with a potential-sensitive carbocyanine dye. Changes of [Ca2+]i were monitored in single myometrial cells loaded with the fluorescent calcium-sensitive probe fura-2. Cells exposed to 100 microM A1242 showed a delayed and sustained increase of [Ca2+]i, and this increase was completely blocked in the absence of extracellular calcium or the presence of nifedipine. Therefore, the data suggest that depolarization of the cell membrane by A1242 enabled myometrial cells to increase [Ca2+]i through activation of voltage-operated calcium channels, and the increased [Ca2+]i consequently stimulated contraction of uterine smooth muscle.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0041-008X
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Academic Press.
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
155
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
261-72
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:10079212-Animals, pubmed-meshheading:10079212-Aroclors, pubmed-meshheading:10079212-Calcium, pubmed-meshheading:10079212-Calcium Channels, pubmed-meshheading:10079212-Carbachol, pubmed-meshheading:10079212-Cell Membrane, pubmed-meshheading:10079212-Cells, Cultured, pubmed-meshheading:10079212-Environmental Pollutants, pubmed-meshheading:10079212-Extracellular Space, pubmed-meshheading:10079212-Female, pubmed-meshheading:10079212-Intracellular Fluid, pubmed-meshheading:10079212-Ion Channel Gating, pubmed-meshheading:10079212-Myometrium, pubmed-meshheading:10079212-Nicotinic Agonists, pubmed-meshheading:10079212-Pregnancy, pubmed-meshheading:10079212-Rats, pubmed-meshheading:10079212-Rats, Sprague-Dawley, pubmed-meshheading:10079212-Stimulation, Chemical, pubmed-meshheading:10079212-Uterine Contraction
pubmed:year
1999
pubmed:articleTitle
Stimulation of oscillatory uterine contraction by the PCB mixture Aroclor 1242 may involve increased [Ca2+]i through voltage-operated calcium channels.
pubmed:affiliation
Department of Environmental and Industrial Health, The University of Michigan, Ann Arbor, Michigan, 48109-2029, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.