Linked Life Data

2498864

Source:http://linkedlifedata.com/resource/pubmed/id/2498864

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1989-6-27
pubmed:abstractText
Previous studies in the rat in vivo have demonstrated that co-injection of methyl mercury (MeHg) with L-cysteine into the common carotid artery enhances brain Hg levels following a single capillary pass through the CNS vasculature. In order to elucidate the relationship between MeHg transport and the neutral amino acid transport carrier system, regulatory aspects of MeHg transport across the bovine blood-brain barrier were investigated in isolated brain microvessel preparations. Following 1 hour co-incubations of 203Hg-MeHgCl with 0.1 mM L-cysteine at 37 degrees, 203Hg uptake by suspended microvessels was significantly increased (P less than 0.05) compared with controls. This enhanced capillary uptake of 203Hg was abolished by co-incubations of microvessels with 0.1 mM L-cysteine-L-methionine, or 0.1 mM L-cysteine plus AT-125 (alpha S, 5S)-alpha-amino-3-chloro-4,5-dihydro-5-isoxazolacetic acid), an irreversible inhibitor of gamma-glutamyl-transpeptidase. One hr co-incubations of bovine capillaries with 203Hg-MeHgCl and 0.1 mM D-cysteine at 37 degrees or 0.1 mM L-cysteine at 0 degrees did not increase rat of 203Hg uptake compare with controls. These results indicate that L-cysteine enhances the rate of capillary MeHg uptake. The accumulation of 203Hg in the bovine microvessels appears to be a carrier-mediated process. It is inhibited by L-methionine, a competitive substrate for neutral amino acid transport, and by AT-125. Capillary uptake of 203Hg is stereospecific to the L-enantiomorph of cysteine, suggesting selective uptake of MeHg across the blold-brain barrier. The data emphasize the relationship between the L-enantiomorph neutral amino acid carrier system and MeHg transport across the capillaries.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0901-9928
pubmed:author
pubmed:issnType
Print
pubmed:volume
64
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
293-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Methyl mercury uptake across bovine brain capillary endothelial cells in vitro: the role of amino acids.
pubmed:affiliation
Environmental Health Sciences Center, University of Rochester, School of Medicine and Dentistry, New York 14642.
pubmed:publicationType
Journal Article, In Vitro