Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1997-2-18
pubmed:abstractText
The intestinal absorption of glycosylated somatostatin analogs was compared in rat enterocyte brush border membranes as an in vitro test system and rats as an in situ absorption model. Derivatives of the cyclic octapeptide octreotide with mono-, di-, and trisaccharide residues were used. The uptake of octreotide by the vesicles was inhibited by the glycosylated analogs. The uptake was not inhibited by the bicyclic octapeptide alpha-amanitin, which exhibits structural similarity but is not absorbed in rats. The inhibition of octreotide permeation into the vesicles decreased in the presence of derivatives with an increasing length of the carbohydrate residues. To evaluate, whether the vesicle system is predictable for the in situ situation, the extent of absorption of the peptides was determined after intrajejunal administration. A linear relationship between inhibitory capacity of the octreotide derivatives in the vesicle system and their in situ absorption efficiency was found when blood was taken from a mesenteric vein. However, after sampling from a peripheral vein, deviations from the predicted values were noted. These differences reflected changes in pharmacokinetics (e.g., hepatic elimination) rather than in absorption. In summary, the data indicate that the vesicle system is a useful tool to predict the absorption efficiency of glycosylated somatostatin analogs in situ.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-3549
pubmed:author
pubmed:issnType
Print
pubmed:volume
85
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1211-4
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Intestinal absorption of sugar-coupled somatostatin analogs.
pubmed:affiliation
Institut für Pharmazeutische Technologie und Biopharmazie, im Neuenheimer Feld, Heidelberg, Germany.
pubmed:publicationType
Journal Article, In Vitro