Linked Life Data

8818821

Source:http://linkedlifedata.com/resource/pubmed/id/8818821

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1996-12-3
pubmed:abstractText
Research from this laboratory has recently demonstrated that the omasal epithelium of sheep is capable of absorbing dipeptides. In order to express proteins potentially responsible for the mediated absorption of small peptides, size-fractionated poly(A)+RNA (RNA) isolated from omasal epithelial tissue of sheep (average BW 67.5 kg) were injected into defolliculated Xenopus laevis oocytes. The ability of oocytes injected with RNA or water to absorb [14C]glycyl-L-sarcosine (Gly-Sar) from media (usually pH 5.5) was compared. After 4 d (P < .02) of culture, specific RNA fractions induced an increased (P < .02) rate of Gly-Sar absorption, as compared with water-injected oocytes. The dependency of Gly-Sar uptake on the presence of a pH gradient was evaluated at pH 5.0, 5.5, 6.0, 6.5, and 7.5. Inducible uptake increased (P < .001) in the presence of increasing proton concentrations, whereas endogenous uptake of Gly-Sar decreased (P < .001). At pH 5.5, induced Gly-Sar uptake was saturable (Kt = .4 mM), but endogenous uptake was not. The specificity of Gly-Sar absorption was studied by the co-incubation of .1 mM Gly-Sar with 5 mM levels of competing substrates (pH 5.5). Induced uptake was inhibited (P < .05) 44% by carnosine, 94% by methionylglycine, and 91% by glycylleucine, but not by glycine. Incubation of RNA with DNA oligomers that were complementary to the rabbit intestinal transporter completely inhibited (P < .05) induced Gly-Sar uptake. These results indicate that sheep omasal epithelial cells express messenger RNA that encode for proteins that are capable of H(+)-dependent dipeptide transport activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-8812
pubmed:author
pubmed:issnType
Print
pubmed:volume
74
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1720-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Demonstration and characterization of dipeptide transport system activity in sheep omasal epithelium by expression of mRNA in Xenopus laevis oocytes.
pubmed:affiliation
Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24601-0306, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't