Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1990-2-2
pubmed:abstractText
Clinical and experimental studies have shown that citrate markedly enhances the intestinal absorption of aluminum (Al), but the site and mechanism of enhanced absorption are unknown. To determine where in the gastrointestinal tract aluminum citrate (Alcitr) was absorbed. Alcitr was gavaged with D-[1-3H] glucose in male Sprague-Dawley rats. Plasma Al levels increased rapidly and simultaneously peaked with D-[1-3G] glucose, suggesting early proximal bowel absorption. In in vitro duodenal and jejunal everted gut preparations, Alcitr incubation resulted in increased tissue Al levels and markedly enhanced transmural transport of Al and citr. Unlike citr, the transmural movement of Al was independent of temperature (37 degrees C vs. 4 degrees C). On the other hand, Al lactate (al Lac) increased tissue associated Al levels but had no effect on transmural Al movement. To determine if this large flux of Al following Alcitr administration was due to paracellular movement, ruthenium red and Ussing chamber studies were used to evaluate the morphologic and functional integrity of cellular tight junctions. Alcitr, as opposed to AlCl3, markedly increased ruthenium red deposits in intercellular spaces, especially around goblet cells, and induced a prolonged significant reduction in transmural resistance. Alcitr also resulted in rapid and nearly complete (99.7%) chelation of free calcium, an event known to disrupt cellular tight junction integrity. Taken together, these data suggest that enhanced Al absorption following administration of Alcitr occurs in the proximal bowel via the paracellular pathway due to the opening of cellular tight junctions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0085-2538
pubmed:author
pubmed:issnType
Print
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
978-84
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Site and mechanism of enhanced gastrointestinal absorption of aluminum by citrate.
pubmed:affiliation
Department of Medicine, Veterans Administration Medical Center, Denver, Colorado.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't