Linked Life Data

14648099

Source:http://linkedlifedata.com/resource/pubmed/id/14648099

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-3-4
pubmed:abstractText
We used the Aplysia californica intestinal epithelium to investigate the effect of alanine-stimulated Na+ absorption on apical membrane exocytosis and whether stimulated exocytosis requires intact actin filaments. The fluid-phase marker fluorescein dextran was used to determine rates of apical membrane exocytosis. L-alanine significantly increased apical exocytosis by approximately 30% compared to controls, and there is a modest, positive correlation between alanine-stimulated exocytosis and short-circuit current (ISC). Thus, apical exocytosis is modulated to some extent by the magnitude of Na+ and alanine entry across the apical membrane. Apical exocytosis is also responsive to virtually any increase in Na+ and alanine entry because increments in alanine-stimulated ISC as small as 1 microA/cm2 stimulated exocytosis. We used D-alanine to determine which parameter (sensitivity to transport vs. magnitude of transport) was most important in activation of apical exocytosis. D-alanine-stimulated ISC was one-sixth that of L-alanine, but stimulated exocytosis was only 29% less than that of L-alanine. Therefore, the apical exocytic system is more responsive to small increases in transport than to the magnitude of transport. Latrunculin A (Lat-A) disrupts the actin cytoskeleton and reduced constitutive apical exocytosis by approximately 65% and completely abolished alanine-stimulated exocytosis. Hence, constitutive exocytosis and alanine-stimulated exocytosis require actin filaments for recruitment of vesicles to the apical membrane. During nutrient absorption, actin filament-regulated apical exocytosis may represent a negative feedback system that modulates apical membrane tension.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0174-1578
pubmed:author
pubmed:issnType
Print
pubmed:volume
174
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
129-38
pubmed:dateRevised
2009-6-8
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Alanine-stimulated exocytosis in Aplysia enterocytes: effect of Na+ transport and requirement for actin filaments.
pubmed:affiliation
Department of Biology, University of Central Arkansas, Conway, AR 72035-5003, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't