Linked Life Data

9879730

Source:http://linkedlifedata.com/resource/pubmed/id/9879730

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1999-4-29
pubmed:abstractText
The novel opioid tetrapeptides, endomorphin-1 and endomorphin-2, recently isolated from bovine and human brain bind with high affinity and selectivity to central mu-opioid receptors. In the digestive tract, a comprehensive pharmacological analysis of the receptors involved in endomorphin action has not been reported. In this study, we analyzed the effects of endomorphin-1 and endomorphin-2 on longitudinal muscle-myenteric plexus preparations (LMMPs) from the guinea-pig ileum. Both peptides (30 pM - 1 microM) inhibited (-log EC50 values: 8.61 and 8.59, respectively) the amplitude of electrically-induced twitch contractions in a concentration-dependent fashion, up to its abolition. Conversely, in unstimulated LMMPs, they failed to affect contractions to applied acetylcholine (100 nM). In stimulated LMMPs, the highly selective mu-opioid receptor antagonist, D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP), caused a concentration-dependent (30 nM-1 microM), parallel rightward shift of endomorphin-1 and endomorphin-2 inhibitory curves, without depression of their maximum. Following Schild analysis, calculated pA2 values were 7.81 and 7.85, respectively, with slopes not different from unity. Concentration-response curves to both peptides were not affected by 30 nM naltrindole (a selective delta-receptor antagonist) or 30 nM nor-binaltorphimine (a selective kappa-receptor antagonist). These results demonstrate that endomorphins selectively activate mu-opioid receptors located on excitatory myenteric plexus neurons, and that they act as full agonists.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0028-1298
pubmed:author
pubmed:issnType
Print
pubmed:volume
358
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
686-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Endomorphin-1 and endomorphin-2 activate mu-opioid receptors in myenteric neurons of the guinea-pig small intestine.
pubmed:affiliation
Department of Internal Medicine and Therapeutics, University of Pavia, Italy. tonini@ipv36.unipv.it
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't