Linked Life Data

3387459

Source:http://linkedlifedata.com/resource/pubmed/id/3387459

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1988-8-11
pubmed:abstractText
The existence of an endogenous antiopiate system which counteracts endogenous opiate effects has been proposed. The present study set out to seek substance/s with morphine-antagonist activity in the brain and serum of morphine-tolerant rats. Cerebral extracts were partly purified on Sephadex G 25 and serum was ultrafiltered through membranes with pore diameter smaller than 0.005 micron. On the guinea pig ileum myenteric plexus longitudinal muscle a fraction of the cerebral extract and the serum ultrafiltrate in toto did increase electrically induced contractions, and antagonized the depressant effect of morphine. The serum ultrafiltrate also enhanced longitudinal smooth muscle tone. Preliminary findings suggest that levels of endogenous morphine-antagonist substance/s are higher in morphine-tolerant rats than in controls. Only cerebral extract, not serum ultrafiltrate, inhibited [3H]-naloxone binding to cerebral opiate receptors. In the guinea pig bioassay both the cerebral extract and serum ultrafiltrate antagonized, to some extent, the inhibition elicited by morphine, norepinephrine and adenosine. These observations support the existence of endogenous compound/s which may be functional antagonist/s of opiates and play a role in the development of tolerance and dependence.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0031-6989
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
307-22
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Cerebral extract from morphine-tolerant rats shows antiopiate properties in guinea pig ileum bioassay.
pubmed:affiliation
Institute of Pharmacology, Faculty of Sciences, University of Milan, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't