Source:http://linkedlifedata.com/resource/pubmed/id/16266723
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
19
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pubmed:dateCreated |
2006-3-27
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pubmed:abstractText |
Mitragynine is an indole alkaloid isolated from the Thai medicinal plant Mitragyna speciosa that is reported to have opioid agonistic properties. The 9-demethyl analogue of mitragynine, 9-hydroxycorynantheidine, is synthesized from mitragynine. 9-Hydroxycorynantheidine inhibited electrically stimulated guinea-pig ileum contraction, but its maximum inhibition was weaker than that of mitragynine and its effect was antagonized by naloxone, suggesting that 9-hydroxycorynantheidine possesses partial agonist properties on opioid receptors. Receptor binding assays revealed that 9-hydroxycorynantheidine has high affinity for mu-opioid receptors. In an assay of the guinea-pig ileum, naloxone shifted the concentration-response curves for [D-Ala(2), N-MePhe(4), Gly-ol(5)]-enkephalin (DAMGO), (5alpha,7alpha,8beta)-(+)-N-Methyl-N-[7-(1-pyrrolidinyl)-1-oxaspiro[4.5]dec-8-yl]-benzeneacetamide (U69593) and 9-hydroxycorynantheidine to the right in a competitive manner. The pA(2) values of naloxone against 9-hydroxycorynantheidine and DAMGO were very similar, but not that against U69593. As indicated by the two assay systems, the opioid effect of 9-hydroxycorynantheidine is selective for the mu-opioid receptor. 9-Hydroxycorynantheidine shifted the concentration-response curve for DAMGO slightly to the right. Pretreatment with the mu-opioid selective and irreversible antagonist beta-funaltorexamine hydrochloride (beta-FNA) shifted the concentration-response curve for DAMGO to the right without affecting the maximum response. On the other hand, beta-FNA did not affect the curve for 9-hydroxycorynantheidine, but decreased the maximum response because of the lack of spare receptors. These studies suggest that 9-hydroxycorynantheidine has partial agonist properties on mu-opioid receptors in the guinea-pig ileum.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Apr
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pubmed:issn |
0024-3205
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
4
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pubmed:volume |
78
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
2265-71
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:16266723-Animals,
pubmed-meshheading:16266723-Binding, Competitive,
pubmed-meshheading:16266723-Brain,
pubmed-meshheading:16266723-Electric Stimulation,
pubmed-meshheading:16266723-Guinea Pigs,
pubmed-meshheading:16266723-Ileum,
pubmed-meshheading:16266723-Indole Alkaloids,
pubmed-meshheading:16266723-Male,
pubmed-meshheading:16266723-Molecular Structure,
pubmed-meshheading:16266723-Muscle, Smooth,
pubmed-meshheading:16266723-Muscle Contraction,
pubmed-meshheading:16266723-Protein Binding,
pubmed-meshheading:16266723-Radioligand Assay,
pubmed-meshheading:16266723-Receptors, Opioid, mu,
pubmed-meshheading:16266723-Secologanin Tryptamine Alkaloids
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pubmed:year |
2006
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pubmed:articleTitle |
Partial agonistic effect of 9-hydroxycorynantheidine on mu-opioid receptor in the guinea-pig ileum.
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pubmed:affiliation |
Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences, Josai International University, Togane, Chiba, Japan. kenjiro@jiu.ac.jp
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
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