Linked Life Data

10878444

Source:http://linkedlifedata.com/resource/pubmed/id/10878444

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-10-19
pubmed:abstractText
We have examined the intracellular route, coenzyme conversion and transcytosis rate of [(57) Co]-labeled cobalamin (Cbl) in function of its presentation to the apical side of Caco-2 cells, either free or bound to intrinsic factor (IF). The free-presented Cbl was progressively bound to endogenous transcobalamin II (TCII) which may stem, in part, from a basolateral to apical passage. Its transcytosis was TCII-mediated as it was abolished when antibodies to TCII were added to the apical medium. The apparent permeability coefficient (P(app)) was estimated at 20.8+/-3.6, 103.5+/-17.7, 0.9+/-0.3 x 10(-5) cm/h for TCII-Cbl, IF-Cbl and haptocorrin-Cbl, respectively. Chloroquine inhibited the transcytosis rate of both TCII and IF-bound Cbl in a dose-dependent manner. Approximately 80% of apical Cbl, bound to either exogenous IF or endogenous TCII, was transported to the basolateral side as intact cyano[(57)Co]Cbl whereas the remainder was converted into Ado-Cbl and CH(3)-Cbl within the cells, as shown by HPLC analyses of a 1,000-g pellet and a 12,000-g supernatant. Coenzymatic conversion was virtually abolished by chloroquine. In conclusion, we suggest that apically presented free Cbl is internalized via TCII-dependent transport. The apically internalized CN-Cbl, bound to either IF or TCII, is processed via an acidic vesicle and part of it is converted to coenzymes, whereas bulk of CN-Cbl is transcytosed intact.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1015-8987
pubmed:author
pubmed:issnType
Print
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
135-48
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Transcytosis and coenzymatic conversion of [(57)Co]cobalamin bound to either endogenous transcobalamin II or exogenous intrinsic factor in caco-2 cells.
pubmed:affiliation
Laboratoire de Pathologie Cellulaire et Moléculaire en Nutrition, Equipe INSERM 00-14, Faculté de Médecine, Université Henri Poincaré, B.P. 184, 54 505 Vandoeuvre-lès-Nancy Cedex, France.
pubmed:publicationType
Journal Article