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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-2-19
pubmed:abstractText
The effects of morphine withdrawal and challenge doses (10 or 30 mg/kg) on the alpha-methyl-p-tyrosine (alpha MT)-induced noradrenaline (NA) depletion as well as on the free 3-methoxy-4-hydroxyphenylethylene glycol (MOPEG) concentration were studied in various brain areas of NMRI mice. Morphine was given subcutaneously 3 times daily for 5 days followed by 1 or 3 days' withdrawal. In morphine withdrawn mice the alpha MT-induced NA depletion and the free MOPEG concentrations were differentially altered. At 1-day withdrawal the alpha MT-induced NA depletion was retarded and the NA concentration was elevated in the forebrain area indicating reduced release of NA. Simultaneously, however, the free MOPEG concentration was significantly elevated in the forebrain area and in the lower brain stem suggesting enhanced NA turnover. No withdrawal-induced changes were found in the hypothalamic NA turnover. Acute morphine elevated the free MOPEG concentration and accelerated the alpha MT-induced NA depletion in all brain areas of control mice but not in mice withdrawn for 1 day from repeated morphine treatment. At 3 days' withdrawal, however, the 30 mg/kg morphine dose slightly accelerated the NA depletion in the forebrain area. These results show that morphine withdrawal differentially alters the alpha MT-induced NA depletion and the free MOPEG concentration in various mouse brain areas. These effects are relatively modest suggesting that in mice the noradrenergic mechanisms play a minor role in morphine withdrawal syndrome. However, in all brain areas of the morphine-withdrawn mice tolerance was found towards the NA turnover and release accelerating effect of acute morphine.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0901-9928
pubmed:author
pubmed:issnType
Print
pubmed:volume
77
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
196-203
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:8884883-Analysis of Variance, pubmed-meshheading:8884883-Animals, pubmed-meshheading:8884883-Brain Stem, pubmed-meshheading:8884883-Chromatography, High Pressure Liquid, pubmed-meshheading:8884883-Dose-Response Relationship, Drug, pubmed-meshheading:8884883-Enzyme Inhibitors, pubmed-meshheading:8884883-Hypothalamus, pubmed-meshheading:8884883-Injections, Subcutaneous, pubmed-meshheading:8884883-Male, pubmed-meshheading:8884883-Methoxyhydroxyphenylglycol, pubmed-meshheading:8884883-Methyltyrosines, pubmed-meshheading:8884883-Mice, pubmed-meshheading:8884883-Morphine, pubmed-meshheading:8884883-Motor Activity, pubmed-meshheading:8884883-Narcotics, pubmed-meshheading:8884883-Norepinephrine, pubmed-meshheading:8884883-Prosencephalon, pubmed-meshheading:8884883-Substance Withdrawal Syndrome, pubmed-meshheading:8884883-alpha-Methyltyrosine
pubmed:year
1995
pubmed:articleTitle
Regional differences in cerebral noradrenaline turnover in mice withdrawn from repeated morphine treatment and tolerance to the effects of acute morphine.
pubmed:affiliation
Department of Pharmacy, University of Helsinki, Finland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't