Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2005-2-3
pubmed:abstractText
It has been shown previously that the endogenous opioid system may be involved in the behavioral effects of nicotine. In the present study, the participation of endogenous enkephalins on nicotine responses has been investigated by using preproenkephalin knock-out mice. Acute nicotine-induced hypolocomotion remained unaffected in these mice. In contrast, antinociception elicited in the tail-immersion and hot-plate tests by acute nicotine administration was reduced in mutant animals. The rewarding properties of nicotine were then investigated using the place-conditioning paradigm. Nicotine induced a conditioned place preference in wild-type animals, but this effect was absent in knock-out mice. Accordingly, in vivo microdialysis studies revealed that the enhancement in dopamine extracellular levels in the nucleus accumbens induced by nicotine was also reduced in preproenkephalin-deficient mice. Finally, the somatic expression of the nicotine withdrawal syndrome precipitated in nicotine-dependent mice by mecamylamine was significantly attenuated in mutant animals. In summary, the present results indicate that endogenous opioid peptides derived from preproenkephalin are involved in the antinociceptive and rewarding properties of nicotine and participate in the expression of physical nicotine dependence.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
2
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1103-12
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:15689546-Analgesics, pubmed-meshheading:15689546-Animals, pubmed-meshheading:15689546-Conditioning, Classical, pubmed-meshheading:15689546-Dopamine, pubmed-meshheading:15689546-Enkephalins, pubmed-meshheading:15689546-Female, pubmed-meshheading:15689546-Hot Temperature, pubmed-meshheading:15689546-Male, pubmed-meshheading:15689546-Mecamylamine, pubmed-meshheading:15689546-Mice, pubmed-meshheading:15689546-Mice, Inbred C57BL, pubmed-meshheading:15689546-Mice, Knockout, pubmed-meshheading:15689546-Microdialysis, pubmed-meshheading:15689546-Motor Activity, pubmed-meshheading:15689546-Nicotine, pubmed-meshheading:15689546-Nucleus Accumbens, pubmed-meshheading:15689546-Opioid Peptides, pubmed-meshheading:15689546-Pain Measurement, pubmed-meshheading:15689546-Pain Threshold, pubmed-meshheading:15689546-Protein Precursors, pubmed-meshheading:15689546-Reward, pubmed-meshheading:15689546-Spatial Behavior, pubmed-meshheading:15689546-Substance Withdrawal Syndrome, pubmed-meshheading:15689546-Tobacco Use Disorder
pubmed:year
2005
pubmed:articleTitle
Nicotine-induced antinociception, rewarding effects, and physical dependence are decreased in mice lacking the preproenkephalin gene.
pubmed:affiliation
Laboratori de Neurofarmacologia, Facultat de Ciències de la Salut i de la Vida, Universitat Pompeu Fabra, Barcelona, Spain.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural