Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1992-4-23
pubmed:abstractText
1. We assessed the efficacy of nitrogen absorption from luminal L-leucine (1.2 and 12 mmol/l) and from isonitrogenous L-leucyl-L-leucine (0.6 and 6.0 mmol/l) in a preparation of vascularly and luminally perfused rat small intestine by measuring luminal leucyl-leucine disappearance and venous leucine appearance. 2. No intact dipeptide was found in the vascular perfusate. Leucine-nitrogen absorption, as judged by venous leucine appearance, was as efficient from free leucine (29 +/- 3 and 245 +/- 19 ng-atom min-1 g-1) as from leucyl-leucine (27 +/- 4 and 211 +/- 58 ng-atom min-1 g-1). It was not reduced in the presence of glycyl-L-proline or of the brush-border dipeptidase inhibitors alanine-beta-naphthylamide and cilastatin. 3. After one passage of the whole small intestine, only trace amounts of dipeptide, but large amounts of free leucine, were detected in the luminal effluent. Peptidase activity in the luminal effluent was demonstrated in 100,000 g supernatant and was inhibited by p-hydroxy-mercuribenzoate, but not by brush-border dipeptidase inhibitors. 4. We propose that nitrogen absorption from luminal leucyl-leucine may proceed predominantly via intraluminal peptide hydrolysis and subsequent transport of free leucine. Nevertheless, our findings and conclusions are at variance with previous observations and current opinion on intestinal handling of dipeptides, which may be due, in part, to the different methodological approach.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0143-5221
pubmed:author
pubmed:issnType
Print
pubmed:volume
82
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
283-90
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Nitrogen absorption from isonitrogenous solutions of L-leucyl-L-leucine and L-leucine: a study in the isolated perfused rat small intestine.
pubmed:affiliation
Eberhard-Karls-Universität, Medizinische Klinik und Poliklinik, Tübingen, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't